Receivables [Abstract] Schedule of Financing Receivable, Allowance for Credit Losses [Table] Schedule of Financing Receivable, Allowance for Credit Losses [Table] Financing Receivable Portfolio Segment [Axis] Financing Receivable Portfolio Segment [Axis] Financing Receivable Portfolio Segment [Domain] Financing Receivable Portfolio Segment [Domain] Commercial Commercial Portfolio Segment [Member] Real Estate Real Estate Portfolio Segments [Member] Real Estate Portfolio Segments [Member] Construction and Land Development Construction And Land Development Portfolio Segment [Member] Construction And Land Development Portfolio Segment [Member] Consumer and Single Family Mortgages Consumer and Residential Single Family Portfolio Segments [Member] Consumer and Residential Single Family Portfolio Segment [Member] Unallocated Unallocated Financing Receivables [Member] Financing Receivable, Allowance for Credit Losses [Line Items] Financing Receivable, Allowance for Credit Losses [Line Items] Allowance for Loan and Lease Losses [Roll Forward] Allowance for Loan and Lease Losses [Roll Forward] Balance at beginning of period Loans and Leases Receivable, Allowance Charge offs Allowance for Loan and Lease Losses, Write-offs Recoveries Allowance for Loan and Lease Loss, Recovery of Bad Debts Provision Provision for Loan and Lease Losses Balance at end of period Segment Reporting [Abstract] Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Consolidation Items [Axis] Consolidation Items [Axis] Consolidation Items [Domain] Consolidation Items [Domain] Operating segment Operating Segments [Member] Other Corporate, Non-Segment [Member] Segments [Axis] Segments [Axis] Segments [Domain] Segments [Domain] Commercial Commercial Banking [Member] Commercial Banking [Member] Segment Reporting Information [Line Items] Segment Reporting Information [Line Items] Net interest income Interest Income (Expense), Net Noninterest Income Noninterest Income Assets Assets Equity [Abstract] Shareholders' Equity Stockholders' Equity Note Disclosure [Text Block] Statement of Financial Position [Abstract] Loans, allowances Preferred stock, shares authorized (in shares) Preferred Stock, Shares Authorized Preferred stock, shares issued (in shares) Preferred Stock, Shares Issued Preferred stock, shares outstanding (in shares) Preferred Stock, Shares Outstanding Common stock, shares authorized (in shares) Common Stock, Shares Authorized Common stock, shares issued (in shares) Common Stock, Shares, Issued Common stock, shares outstanding (in shares) Common Stock, Shares, Outstanding Accounting Policies [Abstract] New Accounting Pronouncements or Change in Accounting Principle [Table] New Accounting Pronouncements or Change in Accounting Principle [Table] Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Retained earnings Retained Earnings [Member] New Accounting Pronouncements or Change in Accounting Principle [Line Items] New Accounting Pronouncements or Change in Accounting Principle [Line Items] Cumulative adjustment from adoption of new accounting pronouncements Cumulative Effect of New Accounting Principle in Period of Adoption Statement of Cash Flows [Abstract] Cash Flows From Operating Activities: Net Cash Provided by (Used in) Operating Activities [Abstract] Net income Net Income (Loss) Attributable to Parent Adjustments to reconcile net income to net cash provided by operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Depreciation and amortization Depreciation, Depletion and Amortization, Nonproduction Amortization of premium on securities Accretion (Amortization) of Discounts and Premiums, Investments Net gain on sale of securities available for sale Gain (Loss) on Sale of Investments Net amortization of deferred fees and unearned income on loans Amortization of Deferred Loan Origination Fees, Net Net gain on sales of other real estate owned Gains (Losses) on Sales of Other Real Estate Net gain on sale of premises and equipment Gain (Loss) on Disposition of Property Plant Equipment Net loss on sale of other assets Gain (Loss) on Disposition of Other Assets Stock-based compensation expense Share-based Compensation Other Other Noncash Income (Expense) Changes in operating assets and liabilities: Increase (Decrease) in Operating Capital [Abstract] Net increase in accrued interest receivable Increase (Decrease) in Accrued Interest Receivable, Net Net decrease (increase) in other assets Increase (Decrease) in Other Operating Assets Net increase in deferred taxes Increase (Decrease) in Deferred Income Taxes Net (increase) decrease in income taxes receivable Increase (Decrease) in Income Taxes Receivable Net increase in accrued interest payable Increase (Decrease) in Interest Payable, Net Net (decrease) increase in other liabilities Increase (Decrease) in Other Operating Liabilities Net cash provided by operating activities Net Cash Provided by (Used in) Operating Activities Cash Flows From Investing Activities: Net Cash Provided by (Used in) Investing Activities [Abstract] Net decrease in interest-bearing time deposits with financial institutions Proceeds from (Payments for) in Interest-bearing Deposits in Banks Maturities of and principal payments received on securities available for sale and other stock Proceeds from Sale, Maturity and Collection of Investments Purchase of securities available for sale and other stock Payments to Acquire Marketable Securities Proceeds from sale of securities available for sale and other stock Proceeds from Sale and Maturity of Marketable Securities Purchase of other investments Payments to Acquire Equity Method Investments Proceeds from sale of other real estate owned Proceeds from Sale of Other Real Estate Net increase in loans Payments for (Proceeds from) Loans and Leases Purchases of premises and equipment Payments to Acquire Property, Plant, and Equipment Proceeds from sale of other assets Proceeds from Sale of Loans and Leases Held-for-investment Proceeds from sale of premises and equipment Proceeds from Sale of Property, Plant, and Equipment Net cash used in investing activities Net Cash Provided by (Used in) Investing Activities Cash Flows From Financing Activities: Net Cash Provided by (Used in) Financing Activities [Abstract] Net (decrease) increase in deposits Increase (Decrease) in Deposits Proceeds from borrowings Proceeds from Issuance of Debt Payments of borrowings Repayments of Debt Proceeds from exercise of common stock options Proceeds from Stock Options Exercised Net cash (used in) provided by financing activities Net Cash Provided by (Used in) Financing Activities Net decrease in cash and cash equivalents Cash and Cash Equivalents, Period Increase (Decrease) Cash and Cash Equivalents, beginning of period Cash and Cash Equivalents, at Carrying Value Cash and Cash Equivalents, end of period Supplementary Cash Flow Information: Supplemental Cash Flow Information [Abstract] Cash paid for interest on deposits and other borrowings Interest Paid, Excluding Capitalized Interest, Operating Activities Cash paid for income taxes Income Taxes Paid Non-Cash Investing and Financing Activities: Noncash Investing and Financing Items [Abstract] Transfer of loans into other assets Other Assets, Transfer to Other Assets Other Assets, Transfer to Other Assets Transfer of loans into other real estate owned Real Estate Owned, Transfer to Real Estate Owned Impact of change in accounting principle Non-Cash Impact Of Change In Accounting Principle Non-Cash Impact Of Change In Accounting Principle Assumption of debt upon foreclosure of property Loans Assumed Exchange of common stock for preferred stock Conversion of Stock, Amount Issued Disclosure of Compensation Related Costs, Share-based Payments [Abstract] Number of Shares Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward] Outstanding, beginning of period (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number Granted (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Net of Forfeitures Exercised (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period Forfeited/Canceled (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures in Period Outstanding, end of period (in shares) Option Exercisable, end of period (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number Options Vested, end of period (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Number Weighted- Average Exercise Price Per Share Share Based Compensation Arrangement By Share Based Payment Award Options Weighted Average Exercise Price [Abstract] Share-based Compensation Arrangement by Share-based Payment Award, Options, Weighted Average Exercise Price [Abstract] Weighted Average Exercise Price, beginning of period (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price Granted (in dollars per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price Exercised (in dollars per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price Forfeited/Canceled (in dollars per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Forfeitures in Period, Weighted Average Exercise Price Weighted Average Exercise Price, end of period (in dollars per share) Options Exercisable, end of period (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price Options Vested, end of period (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Exercise Price Fair Value Disclosures [Abstract] Fair Value Measurements Fair Value Disclosures [Text Block] Commitments and Contingencies Disclosure [Abstract] Schedule of Long-term Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] Debt Instrument [Axis] Debt Instrument [Axis] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] 2.34% due November 2018 Debt Instrument, One [Member] Debt Instrument, One [Member] 1.77% due December 2018 Debt Instrument, Two [Member] Debt Instrument, Two [Member] 2.36% due December 2018 Debt Instrument, Three [Member] Debt Instrument, Three [Member] 2.31% due January 2019 Debt Instrument, Four [Member] Debt Instrument, Four [Member] Long-term Debt, Type [Axis] Long-term Debt, Type [Axis] Long-term Debt, Type [Domain] Long-term Debt, Type [Domain] FHLB Advances Federal Home Loan Bank Advances [Member] Debt Instrument [Line Items] Debt Instrument [Line Items] Principal Amounts Debt Instrument, Face Amount Interest Rate Debt Instrument, Interest Rate, Stated Percentage Schedule of Impaired Financing Receivable [Table] Schedule of Impaired Financing Receivable [Table] Loan Receivable by Past Due Status [Axis] Loan Receivable By Past Due Status [Axis] Loan Receivable by Past Due Status [Axis] Loan Receivable by Past Due Status [Domain] Loan Receivable By Past Due Status [Domain] Loan Receivable by Past Due Status [Domain] Impaired loans less than 90 days delinquent and included in total impaired loans Loans Under Ninety Days Past Due [Member] Loans Under Ninety Days Past Due [Member] Financing Receivable, Impaired [Line Items] Financing Receivable, Impaired [Line Items] Impaired loans: Loans and Leases Receivable, Other Information [Abstract] Nonaccruing loans Loans and Leases Receivable, Nonperforming, Nonaccrual of Interest Nonaccruing restructured loans Financing Receivable Modifications Recorded Investment Nonaccrual Financing Receivable, Modifications, Recorded Investment, Nonaccrual Accruing restructured loans Financing Receivable Modifications Recorded Investment Accruing Financing Receivable, Modifications, Recorded Investment, Accruing Total impaired loans Impaired Financing Receivable, Recorded Investment Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Fair Value Measurements, Recurring and Nonrecurring [Table] Fair Value Measurements, Recurring and Nonrecurring [Table] Investment Type [Axis] Investment Type [Axis] Investments [Domain] Investments [Domain] U.S. Treasury securities US Treasury Securities [Member] Commercial mortgage backed securities issued by U.S. Agencies Commercial Mortgage Backed Securities [Member] Residential mortgage backed securities issued by U.S. agencies Residential Mortgage Backed Securities [Member] Asset-backed security Asset-backed Securities [Member] Mutual funds Mutual Funds [Member] Mutual Funds [Member] Measurement Frequency [Axis] Measurement Frequency [Axis] Fair Value, Measurement Frequency [Domain] Fair Value, Measurement Frequency [Domain] Recurring Fair Value, Measurements, Recurring [Member] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Fair Value, Measurements, Fair Value Hierarchy [Domain] Fair Value Hierarchy and NAV [Domain] Level 1 Fair Value, Inputs, Level 1 [Member] Level 2 Fair Value, Inputs, Level 2 [Member] Level 3 Fair Value, Inputs, Level 3 [Member] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Total debt securities available for sale Debt Securities, Available-for-sale Securities available for sale, at fair value Available-for-sale Securities Significant Accounting Policies Significant Accounting Policies [Text Block] Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Commercial loans Commercial real estate loans – owner occupied Commercial Real Estate, Owner Occupied, Portfolio Segment [Member] Commercial Real Estate, Owner Occupied, Portfolio Segment [Member] Commercial real estate loans – all other Commercial Real Estate, All Other, Portfolio Segment [Member] Commercial Real Estate, All Other, Portfolio Segment [Member] Residential mortgage loans – multi-family Residential, Multi-Family, Portfolio Segment [Member] Residential, Multi-Family, Portfolio Segment [Member] Residential mortgage loans – single family Residential, Single Family, Portfolio Segment [Member] Residential, Single Family, Portfolio Segment [Member] Construction and land development loans Consumer loans Consumer Portfolio Segment [Member] Accounts, Notes, Loans and Financing Receivable [Line Items] Accounts, Notes, Loans and Financing Receivable [Line Items] Gross loans Loans and Leases Receivable, Gross Deferred fee (income) costs, net Loans and Leases Receivable, Deferred Fee (Income) Costs, Net Loans and Leases Receivable, Deferred Fee (Income) Costs, Net Allowance for loan and lease losses Loans, net Loans and Leases Receivable, Net Amount Percentage of loan portfolio Percentage Of Loan Portfolio Percentage Of Loan Portfolio Schedule of Stock by Class [Table] Schedule of Stock by Class [Table] Series A Non-Voting Preferred stock Preferred Stock [Member] Common stock Common Stock [Member] Legal Entity [Axis] Legal Entity [Axis] Entity [Domain] Entity [Domain] Patriot Financial Partners III, LP Patriot Financial Partners III, LP [Member] Patriot Financial Partners III, LP [Member] Class of Stock [Axis] Class of Stock [Axis] Class of Stock [Domain] Class of Stock [Domain] Series A Preferred Stock Series A Preferred Stock [Member] Class of Stock [Line Items] Class of Stock [Line Items] Exchange of common stock for Series A Non-Voting Preferred Stock (in shares) Stock Issued During Period, Shares, Conversion of Convertible Securities Number of shares acquired Business Acquisition, Number Of Shares Acquired Business Acquisition, Number Of Shares Acquired Preferred stock, liquidation preference (in dollars per share) Preferred Stock, Liquidation Preference Per Share Percentage of voting interests acquired Business Acquisition, Percentage of Voting Interests Acquired Net Interest Income and Noninterest Income Schedule of Segment Reporting Information, by Segment [Table Text Block] Composition of Loan Portfolio Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block] Allowance for Loan Losses and Loan Balances Allowance for Credit Losses on Financing Receivables [Table Text Block] Summary of Delinquency Status of Loans by Portfolio Type Past Due Financing Receivables [Table Text Block] Loans on Nonaccrual Status by Portfolio Type Schedule of Financing Receivables, Non Accrual Status [Table Text Block] Summary of Loans by Portfolio Type and Internal Credit Quality Ratings Financing Receivable Credit Quality Indicators [Table Text Block] Schedule of Impaired Loans Impaired Financing Receivables [Table Text Block] Troubled Debt Restructurings Troubled Debt Restructurings on Financing Receivables [Table Text Block] Earnings Per Share [Abstract] Schedule of Earnings Per Share, Basic, by Common Class, Including Two Class Method [Table] Schedule of Earnings Per Share, Basic, by Common Class, Including Two Class Method [Table] Award Type [Axis] Award Type [Axis] Equity Award [Domain] Equity Award [Domain] Restricted stock Restricted Stock [Member] Stock options Employee Stock Option [Member] Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items] Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items] Basic EPS: Earnings Per Share, Basic [Abstract] Less dividends on preferred stock Preferred Stock Dividends, Income Statement Impact Less dividends on common stock Dividends, Common Stock Less dividends on unvested shares Other Preferred Stock Dividends and Adjustments Net income allocable to common shareholders Net Income (Loss) Available To Common Stockholders, Before Allocation To Participating Securities, Basic Net Income (Loss) Available To Common Stockholders, Before Allocation To Participating Securities, Basic Less earnings allocated to participating securities Undistributed Earnings (Loss) Allocated to Participating Securities, Basic Net income allocable to common shareholders Net Income (Loss) Available to Common Stockholders, Basic Weighted average common shares outstanding (in shares) Weighted Average Number of Shares Outstanding, Basic Basic earnings per common share (in dollars per share) Earnings Per Share, Basic Diluted EPS: Earnings Per Share, Diluted [Abstract] Earnings allocated to common shareholders Net Income (Loss) Attributable to Parent, Diluted Add dilutive effects of restricted stock grants and stock options Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements Add dilutive effects for assumed conversion of Series A preferred stock Incremental Common Shares Attributable to Dilutive Effect of Conversion of Preferred Stock Weighted average diluted common shares outstanding (in shares) Weighted Average Number of Shares Outstanding, Diluted Diluted earnings per common share (in dollars per share) Earnings Per Share, Diluted Investments [Abstract] Debt Securities, Available-for-sale [Table] Debt Securities, Available-for-sale [Table] Adjustments for New Accounting Pronouncements [Axis] Adjustments for New Accounting Pronouncements [Axis] Type of Adoption [Domain] Type of Adoption [Domain] ASU 2016-01 Accounting Standards Update 2016-01 [Member] Residential mortgage backed securities issued by U.S. Agencies Debt Securities, Available-for-sale [Line Items] Debt Securities, Available-for-sale [Line Items] Less than 12 months, Fair Value Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months Less than 12 months, Unrealized Loss Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss 12 months or more, Fair Value Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer 12 months or more, Unrealized Loss Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss Total, Fair Value Debt Securities, Available-for-sale, Unrealized Loss Position Total, Unrealized Loss Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract] Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract] Less than 12 months, Fair Value Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value Less than 12 months, Unrealized Loss Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss 12 months or more, Fair Value Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value 12 months or more, Unrealized Loss Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss Total, Fair Value Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value Total, Unrealized Loss Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss Statement of Stockholders' Equity [Abstract] Statement [Table] Statement [Table] Retained earnings (accumulated deficit) Accumulated other comprehensive income (loss) AOCI Attributable to Parent [Member] Statement [Line Items] Statement [Line Items] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Beginning Balance (in shares) Shares, Issued Beginning Balance Stockholders' Equity Attributable to Parent Exchange of common stock for Series A Non-Voting Preferred Stock Stock Issued During Period, Value, Conversion of Convertible Securities Implementation of ASU 2016-01 Issuance of restricted stock, net (in shares) Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures Common stock based compensation expense Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures Common stock options exercised (in shares) Common stock options exercised Stock Issued During Period, Value, Stock Options Exercised Net income Other comprehensive loss Other Comprehensive Income (Loss), Net of Tax Ending Balance (in shares) Ending Balance ASSETS Assets [Abstract] Cash and due from banks Cash and Due from Banks Interest bearing deposits with financial institutions Interest-bearing Deposits in Banks and Other Financial Institutions Cash and cash equivalents Interest-bearing time deposits with financial institutions Time Deposits, at Carrying Value Federal Reserve Bank of San Francisco and Federal Home Loan Bank Stock, at cost Federal Home Loan Bank Stock and Federal Reserve Bank Stock Loans (net of allowances of $13,463 and $14,196, respectively) Other real estate owned Other Real Estate Accrued interest receivable Interest Receivable Premises and equipment, net Property, Plant and Equipment, Net Net deferred tax assets Deferred Income Tax Assets, Net Other assets Other Assets Total assets LIABILITIES AND SHAREHOLDERS’ EQUITY Liabilities and Equity [Abstract] Deposits: Deposits [Abstract] Noninterest-bearing Noninterest-bearing Deposit Liabilities Interest-bearing Interest-bearing Deposit Liabilities Total deposits Deposits Borrowings Debt and Capital Lease Obligations Accrued interest payable Interest Payable Other liabilities Other Liabilities Junior subordinated debentures Junior Subordinated Notes Total liabilities Liabilities Commitments and contingencies (Note 10) Commitments and Contingencies Shareholders’ equity: Stockholders' Equity Attributable to Parent [Abstract] Series A Non-Voting Preferred Stock, no par value, 1,467,155 shares authorized at September 30, 2018 and 0 shares authorized at December 31, 2017; 1,467,155 shares issued and outstanding at September 30, 2018 and 0 shares issued and outstanding at December 31, 2017 Preferred Stock, Value, Issued Common stock, no par value, 85,000,000 shares authorized; 21,917,995 and 23,232,515 shares issued and outstanding at September 30, 2018 and December 31, 2017, respectively Common Stock, Value, Issued Accumulated deficit Retained Earnings (Accumulated Deficit) Accumulated other comprehensive loss Accumulated Other Comprehensive Income (Loss), Net of Tax Total shareholders’ equity Total liabilities and shareholders’ equity Liabilities and Equity Document and Entity Information [Abstract] Document and Entity Information [Abstract] Entity Registrant Name Entity Registrant Name Entity Central Index Key Entity Central Index Key Current Fiscal Year End Date Current Fiscal Year End Date Entity Filer Category Entity Filer Category Document Type Document Type Document Period End Date Document Period End Date Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Trading Symbol Trading Symbol Amendment Flag Amendment Flag Entity Emerging Growth Company Entity Emerging Growth Company Entity Small Business Entity Small Business Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Antidilutive Securities [Axis] Antidilutive Securities [Axis] Antidilutive Securities, Name [Domain] Antidilutive Securities, Name [Domain] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Anti-dilutive shares excluded from computation of earnings per share (in shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Loans and Allowance for Loan and Lease Losses Loans, Notes, Trade and Other Receivables Disclosure [Text Block] Income Tax Disclosure [Abstract] Net deferred tax assets Deferred Tax Assets, Net Income tax (benefit) provision Income Tax Expense (Benefit) Valuation allowance Deferred Tax Assets, Valuation Allowance Income tax benefit resulted from adjustment of deferred tax asset Income Tax Expense (Benefit), Continuing Operations, Adjustment of Deferred Tax (Asset) Liability Accrued interest or penalties associated with unrecognized tax benefits Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued Interest expense recognized Unrecognized Tax Benefits, Interest on Income Taxes Expense Schedule of Accumulated Other Comprehensive Income (Loss), net Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Statement of Comprehensive Income [Abstract] Other comprehensive (loss) income, net of tax: Other Comprehensive Income (Loss), Net of Tax [Abstract] Change in unrealized holding (loss) gain on securities available for sale Other Comprehensive Income (Loss), Securities, Available-for-Sale, Unrealized Holding Gain (Loss) Arising During Period, after Tax Less: Reclassification adjustment for change in accounting principle Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Securities Subject To Change In Accounting Principles, Net of Tax Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Securities Subject To Change In Accounting Principles, Net of Tax Less: Reclassification adjustment for net gains included in net income Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Net of Tax Net unrealized holding (loss) gain on securities available for sale Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax, Portion Attributable to Parent Total comprehensive income Comprehensive Income (Loss), Net of Tax, Attributable to Parent Regulatory Capital Requirements [Abstract] Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations [Table] Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations [Table] Range [Axis] Range [Axis] Range [Domain] Range [Domain] Minimum Minimum [Member] Company Company [Member] Company [Member] Bank Bank [Member] Bank [Member] Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items] Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items] Total Capital to Risk Weighted Assets Capital [Abstract] Total Capital to Risk Weighted Assets, Actual Capital Amount Capital Total Capital to Risk Weighted Assets, Actual Capital Ratio Capital to Risk Weighted Assets Total Capital to Risk Weighted Assets, For Capital Adequacy Purposes, Amount Capital Required for Capital Adequacy Total Capital to Risk Weighted Assets, For Capital Adequacy Purposes, Ratio Capital Required for Capital Adequacy to Risk Weighted Assets Total Capital to Risk Weighted Assets To be Categorized as Well-capitalized, Amount Capital Required to be Well Capitalized Total Capital to Risk Weighted Assets To be Categorized as Well-capitalized, Ratio Capital Required to be Well Capitalized to Risk Weighted Assets Tier 1 Capital to Risk Weighted Assets Tier One Risk Based Capital [Abstract] Tier 1 Capital to Risk Weighted Assets, Actual Capital Amount Tier One Risk Based Capital Tier 1 Capital to Risk Weighted Asset, Actual Capital Ratio Tier One Risk Based Capital to Risk Weighted Assets Tier 1 Capital to Risk Weighted Assets, For Capital Adequacy Purposes, Amount Tier One Risk Based Capital Required for Capital Adequacy Tier 1 Capital to Risk Weighted Assets, For Capital Adequacy Purposes, Ratio Tier One Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets Tier 1 Capital to Risk Weighted Assets, To be Categorized As Well Capitalized, Amount Tier One Risk Based Capital Required to be Well Capitalized Tier 1 Capital to Risk Weighted Assets, To be Categorized As Well Capitalized, Ratio Tier One Risk Based Capital Required to be Well Capitalized to Risk Weighted Assets Tier 1 Capital to Average Assets Tier One Leverage Capital [Abstract] Tier 1 Capital to Average Assets, Actual Capital Amount Tier One Leverage Capital Tier 1 Capital to Average Asset, Actual Capital Ratio Tier One Leverage Capital to Average Assets Tier 1 Capital to Average Assets, For Capital Adequacy Purposes, Amount Tier One Leverage Capital Required for Capital Adequacy Tier 1 Capital to Average Assets, For Capital Adequacy Purposes, Ratio Tier One Leverage Capital Required for Capital Adequacy to Average Assets Tier 1 Capital to Risk Weighted Assets, To be Categorized As Well Capitalized, Amount Tier One Leverage Capital Required to be Well Capitalized Tier 1 Capital to Average Assets, To be Categorized As Well Capitalized, Ratio Tier One Leverage Capital Required to be Well Capitalized to Average Assets Income Taxes Income Tax Disclosure [Text Block] Actual Amount and Capital Ratios of Company and Bank Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations [Table Text Block] Allowance for loans individually evaluated for impairment Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment Allowance for loans collectively evaluated for impairment Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment Total allowance Loans individually evaluated for impairment Financing Receivable, Individually Evaluated for Impairment Loans collectively evaluated for impairment Financing Receivable, Collectively Evaluated for Impairment Total loans Weighted Average Assumptions used to Determine Fair Values of Options Granted Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block] Stock Option Activity under Plans Share-based Compensation, Stock Options, Activity [Table Text Block] Additional Information Regarding Vested and Unvested Options Outstanding Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding and Exercisable [Table Text Block] Summary of Status of Unvested Options and Changes in Number of Shares Subject to and in Weighted Average Grant Date Fair Values of Unvested Options Share-based Compensation, Activity [Table Text Block] Schedule of Restricted Stock Activity Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity [Table Text Block] Compensation Expense of Non-Vested Stock Options Outstanding Schedule of Unrecognized Compensation Cost, Nonvested Awards [Table Text Block] Securities available for sale, amortized cost Debt Securities, Available-for-sale, Amortized Cost, Fiscal Year Maturity [Abstract] One year or less Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, within One Year, Amortized Cost Over one year through five years Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after One Through Five Years, Amortized Cost Over five years through ten years Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after Five Through Ten Years, Amortized Cost Over ten Years Debt Securities, Available-for-sale, Allocated and Single Maturity Date, Maturity, after 10 Years, Amortized Cost Total Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Amortized Cost Securities available for sale, estimated fair value Debt Securities, Available-for-sale, Fair Value, Fiscal Year Maturity [Abstract] One year or less Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, within One Year, Fair Value Over one year through five years Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after One Through Five Years, Fair Value Over five years through ten years Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after Five Through Ten Years, Fair Value Over ten Years Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after 10 Years, Fair Value Total Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Fair Value Weighted average yield Available-for-sale Securities, Debt Maturities, Weighted Average Yield, Fiscal Year Maturity [Abstract] Available-for-sale Securities, Debt Maturities, Weighted Average Yield, Fiscal Year Maturity [Abstract] One year or less Available For Sale Securities Debt Maturities Within One Year Average Yield Available for sale Securities, Debt Maturities, Within One Year, Average Yield Over one year through five years Available For Sale Securities Debt Maturities After One Through Five Years Average Yield Available for sale Securities, Debt Maturities, After One Through Five Years, Average Yield Over five years through ten years Available For Sale Securities Debt Maturities After Five Through Ten Years Average Yield Available for sale Securities, Debt Maturities, After Five Through Ten Years, Average Yield Over ten Years Available For Sale Securities Debt Maturities After Ten Years Average Yield Available for sale Securities, Debt Maturities, After Ten Years, Average Yield Total Available For Sale Securities Weighted Average Yield Available for sale Securities, Weighted Average Yield Investment [Table] Investment [Table] Investment [Line Items] Investment [Line Items] Schedule of Borrowings and Contractual Obligations Schedule of Debt [Table Text Block] Schedule of FHLB Borrowings Schedule of Federal Home Loan Bank, Advances, by Branch of FHLB Bank [Table Text Block] Schedule of Components of Deferred Tax Asset Schedule of Deferred Tax Assets and Liabilities [Table Text Block] Reportable business segment Number of Reportable Segments Investments Investment [Text Block] Fair Value Measurement Inputs and Valuation Techniques [Table] Fair Value Measurement Inputs and Valuation Techniques [Table] Asset Class [Axis] Asset Class [Axis] Fair Value by Asset Class [Domain] Asset Class [Domain] Assets [Member] Assets [Member] Impaired loans Impaired Loans [Member] Impaired Loans [Member] Valuation Approach and Technique [Axis] Valuation Approach and Technique [Axis] Valuation Approach and Technique [Domain] Valuation Approach and Technique [Domain] Third-Party Pricing Third-Party Pricing Valuation Technique [Member] Third-Party Pricing Valuation Technique [Member] Fair Value Inputs, Assets, Quantitative Information [Line Items] Fair Value Measurement Inputs and Valuation Techniques [Line Items] Assets, fair value disclosure Assets, Fair Value Disclosure Schedule of Financing Receivable, Recorded Investment, Credit Quality Indicator [Table] Schedule of Financing Receivable, Recorded Investment, Credit Quality Indicator [Table] Internal Credit Assessment [Axis] Internal Credit Assessment [Axis] Internal Credit Assessment [Domain] Internal Credit Assessment [Domain] Pass Pass [Member] Special Mention Special Mention [Member] Substandard Substandard [Member] Doubtful Doubtful [Member] Financing Receivable, Recorded Investment [Line Items] Financing Receivable, Recorded Investment [Line Items] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Plan Name [Axis] Plan Name [Axis] Plan Name [Domain] Plan Name [Domain] Equity Incentive Plan 2010 Equity Incentive Plan Twenty Ten [Member] Equity Incentive Plan 2010 [Member] Previously Approved Equity Incentive Plans Previously Approved Equity Incentive Plans [Member] Previously Approved Equity Incentive Plans [Member] Maximum Maximum [Member] Title of Individual [Axis] Title of Individual [Axis] Relationship to Entity [Domain] Relationship to Entity [Domain] Employees Employees [Member] Employees [Member] Directors Director [Member] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Number of shares authorized (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized Additional shares authorized (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized Options outstanding (in shares) Number of accumulated shares vested (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Cumulative Vested Shares Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Cumulative Vested Shares Maximum number of shares available for grant, percent of common stock outstanding Share-based Compensation Arrangement by Share-based Payment Award, Percentage of Outstanding Stock Maximum Purchase price per share of common stock as percentage of fair market value of shares on respective grant dates of stock options Exercise Price As Percentage Of Fair Market Value Of Underlying Shares Exercise Price as Percentage of Fair Market Value of Underlying Shares Options, restricted shares and SARs, vesting period Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period Options and SARs, terms after date of grant Share Based Compensation Arrangement By Share Based Payment Award Expiry Period From Date Of Grant Share Based Compensation Arrangement By Share Based Payment Award Expiry Period From Date Of Grant Options exercised (in shares) Aggregate intrinsic value of options exercised Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value Fair value of options vested Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested in Period, Fair Value Aggregate intrinsic values of options outstanding and exercisable Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding And Exercisable Aggregate Intrinsic Value Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding and Exercisable, Aggregate Intrinsic Value Nonvested awards, expected weighted average recognition period Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition Aggregate amounts of stock based compensation expense, net of taxes Allocated Share-based Compensation Expense, Net of Tax Earnings Per Share ("EPS") Earnings Per Share [Text Block] Business Segment Information Segment Reporting Disclosure [Text Block] Number of Shares Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] Outstanding, at beginning of period (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number Granted (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period Vested (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period Forfeited (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period Outstanding, at end of period (in shares) Average Grant Date Fair Value Per Share Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract] Outstanding, at beginning of period (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value Granted (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value Vested (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value Forfeited (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value Outstanding, at end of period (in dollars per share) Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Asset Backed Securities Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] Changes in Level 3 assets measured at fair value on a recurring basis Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] Balance of recurring Level 3 instruments at December 31, 2017 Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value Total gains or losses (realized/unrealized): Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Assets Total Gains Losses Realized And Unrealized [Abstract] Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Assets, Total Gains (Losses) Realized and Unrealized [Abstract] Included in earnings-realized Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings Included in other comprehensive income Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Other Comprehensive Income (Loss) Sales Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales Settlements Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements Balance of recurring Level 3 instruments at September 30, 2018 Regulatory Capital Regulatory Capital Requirements under Banking Regulations [Text Block] Interim Consolidated Financial Statements Basis of Presentation Basis of Accounting, Policy [Policy Text Block] Use of Estimates Use of Estimates, Policy [Policy Text Block] Principles of Consolidation Consolidation, Policy [Policy Text Block] Recent Accounting Pronouncements New Accounting Pronouncements, Policy [Policy Text Block] Fair Value Measurements Fair Value Measurement, Policy [Policy Text Block] Fair Value, by Balance Sheet Grouping [Table] Fair Value, by Balance Sheet Grouping [Table] Measurement Basis [Axis] Measurement Basis [Axis] Fair Value Measurement [Domain] Fair Value Measurement [Domain] Portion at Fair Value Measurement Portion at Fair Value Measurement [Member] Carrying Value Reported Value Measurement [Member] Total Estimate of Fair Value Measurement [Member] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Financial assets: Assets, Fair Value Disclosure [Abstract] Cash and cash equivalents Cash and Cash Equivalents, Fair Value Disclosure Interest-bearing deposits with financial institutions Interest Bearing Deposits At Other Financial Institutions Fair Value Disclosure Interest Bearing Deposits At Other Financial Institutions Fair Value Disclosure Federal Reserve Bank of San Francisco and Federal Home Loan Bank stock Investment in Federal Home Loan Bank Stock, Fair Value Disclosure Loans, net Loans Receivable, Fair Value Disclosure Accrued interest receivable Accrued Interest Receivable, Fair Value Disclosure Accrued Interest Receivable, Fair Value Disclosure Financial liabilities: Liabilities, Fair Value Disclosure [Abstract] Noninterest bearing deposits Non Interest Bearing Deposit Liabilities Fair Value Disclosure Non Interest Bearing Deposit Liabilities, Fair Value Disclosure Interest-bearing deposits Interest Bearing Deposit Liabilities Fair Value Disclosure Interest Bearing Deposit Liabilities, Fair Value Disclosure Borrowings Federal Home Loan Bank Borrowings, Fair Value Disclosure Junior subordinated debentures Long-term Debt, Fair Value Accrued interest payable Accrued Interest Payable, Fair Value Disclosure Accrued Interest Payable, Fair Value Disclosure Income Statement [Abstract] Interest income: Interest and Dividend Income, Operating [Abstract] Loans, including fees Interest and Fee Income, Loans and Leases Securities available for sale and stock Interest and Dividend Income, Securities, Operating Interest-bearing deposits with financial institutions Interest Income, Deposits with Financial Institutions Total interest income Interest and Dividend Income, Operating Interest expense: Interest Expense [Abstract] Deposits Interest Expense, Deposits Borrowings Interest Expense, Borrowings Total interest expense Interest Expense Net interest income Provision for loan and lease losses Net interest income after provision for loan and lease losses Interest Income (Expense), after Provision for Loan Loss Noninterest income Noninterest Income [Abstract] Service fees on deposits and other banking services Fees and Commissions, Depositor Accounts1 Fees and Commissions, Depositor Accounts1 Net gain on sale of securities available for sale Gain (Loss) on Investments Net (loss) gain on sale of other assets Gain (Loss) on Disposition of Other Financial Assets Other noninterest income Noninterest Income, Other Operating Income Total noninterest income Noninterest expense Noninterest Expense [Abstract] Salaries and employee benefits Labor and Related Expense Occupancy Occupancy, Net Equipment and depreciation Equipment Expense Data processing Information Technology and Data Processing FDIC expense Federal Deposit Insurance Corporation Premium Expense Other real estate owned expense, net Other Real Estate Owned Expense (Income), Net Other Real Estate Owned Expense (Income), Net Professional fees Professional Fees Business development Business Development Loan related expense Loan Portfolio Expense Insurance General Insurance Expense Other operating expense Other Noninterest Expense Total noninterest expense Noninterest Expense Income before income taxes Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest Net income allocable to common shareholders Basic income per common share: Net income allocable to common shareholders (in dollars per share) Diluted income per common share: Net income available to allocable shareholders (in dollars per share) Weighted average number of common shares outstanding: Weighted Average Number of Shares Outstanding, Diluted [Abstract] Basic (in shares) Diluted (in shares) Organization, Consolidation and Presentation of Financial Statements [Abstract] Nature of Business Nature of Operations [Text Block] Recorded Investment, No allowance recorded Impaired Financing Receivable, with No Related Allowance, Recorded Investment Recorded Investment, With allowance recorded Impaired Financing Receivable, with Related Allowance, Recorded Investment Unpaid Principal Balance, No allowance recorded Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance Unpaid Principal Balance, With allowance recorded Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance Unpaid Principal Balance Impaired Financing Receivable, Unpaid Principal Balance Related Allowance Impaired Financing Receivable, Related Allowance Average Balance, No allowance recorded Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment Average Balance, With allowance recorded Impaired Financing Receivable, with Related Allowance, Average Recorded Investment Average Balance Impaired Financing Receivable, Average Recorded Investment Interest Income Recognized, No allowance recorded Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method Interest Income Recognized, With allowance recorded Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method Interest Income Recognized Impaired Financing Receivable, Interest Income, Accrual Method Major Components of Securities Available for Sale and Comparison of Amortized Cost, Estimated Fair Market Values, and Gross Unrealized Gains and Losses Available-for-sale Securities [Table Text Block] Amortized Cost and Estimated Fair Values of Securities Available for Sale by Contractual Maturities and Historical Prepayments based on Prior Twelve Months of Principal Payments Unrealized Gain (Loss) on Investments [Table Text Block] Gross Unrealized Losses and Fair Values of Investments Schedule of Unrealized Loss on Investments [Table Text Block] Schedule of Other Investments Schedule Of Other Investments [Table Text Block] Schedule Of Other Investments [Table Text Block] Deferred tax asset: Deferred Tax Assets, Gross [Abstract] Allowance for loan and lease losses Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Provision for Loan Losses Other than temporary impairment on securities Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Impairment Losses Deferred compensation Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits Litigation reserve Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Legal Settlements Other accrued expenses Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Other Charitable contributions Deferred Tax Assets, Charitable Contribution Carryforwards Reserve for unfunded commitments Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Contingencies Tax credits Deferred Tax Assets, Tax Credit Carryforwards Net operating loss carry forward Deferred Tax Assets, Operating Loss Carryforwards Stock based compensation Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Share-based Compensation Cost Depreciation and amortization Deferred Tax Assets, Property, Plant and Equipment Unrealized losses on securities and deferred compensation Deferred Tax Assets Unrealized Losses Deferred Tax Assets, Unrealized Losses Total deferred tax assets Deferred Tax Assets, Gross Deferred Tax Liabilities, Gross [Abstract] Deferred Tax Liabilities, Gross [Abstract] Depreciation and amortization Deferred Tax Liabilities, Property, Plant and Equipment Other Deferred Tax Liabilities, Other Total deferred tax liabilities Deferred Tax Liabilities, Gross Valuation allowance Total net deferred tax asset Equity investments without readily determinable fair value Equity Securities without Readily Determinable Fair Value, Amount Investments accounted for under the cost method Cost Method Investments Schedule of Financing Receivable, Troubled Debt Restructurings [Table] Schedule of Financing Receivable, Troubled Debt Restructurings [Table] Financial Instrument Performance Status [Axis] Financial Instrument Performance Status [Axis] Financial Instrument Performance Status [Domain] Financial Instrument Performance Status [Domain] Performing Performing Financial Instruments [Member] Nonperforming Nonperforming Financial Instruments [Member] Financing Receivable, Modifications [Line Items] Financing Receivable, Modifications [Line Items] Number of loans Financing Receivable, Modifications, Number of Contracts Pre-Modification Outstanding Recorded Investment Financing Receivable, Modifications, Pre-Modification Recorded Investment Post-Modification Outstanding Recorded Investment Financing Receivable, Modifications, Post-Modification Recorded Investment TDRs that were modified within the preceding 12-month period which subsequently defaulted, number of loans Financing Receivable, Modifications, Subsequent Default, Number of Contracts TDRs that were modified within the preceding 12-month period which subsequently defaulted, recorded investment Financing Receivable, Modifications, Subsequent Default, Recorded Investment Commitment And Contingencies [Table] Commitment And Contingencies [Table] Commitment And Contingencies [Table] Loss Contingency Nature [Axis] Loss Contingency Nature [Axis] Loss Contingency, Nature [Domain] Loss Contingency, Nature [Domain] Unfavorable Regulatory Action Unfavorable Regulatory Action [Member] Credit Facility [Axis] Credit Facility [Axis] Credit Facility [Domain] Credit Facility [Domain] Letter of credit Letter of Credit [Member] Commitment And Contingencies [Line Items] Commitment And Contingencies [Line Items] Commitment And Contingencies [Line Items] Commitment to fund certain loans including letter of credit Guarantor Obligations, Maximum Exposure, Undiscounted Loss reserve for unfunded loan commitments Provision for Other Losses Loans pledged as collateral to support FHLB borrowings Pledged Assets Separately Reported, Loans Pledged as Collateral, at Fair Value Unused borrowing capacity Debt Instrument, Unused Borrowing Capacity, Amount Maximum borrowings outstanding at any month-end Federal Home Loan Bank, Advances, Activity for Year, Maximum Outstanding at any Month End Short-term FHLB advances outstanding Federal Home Loan Bank, Advances, Maturities Summary, Due in Next Twelve Months FHLB advances—long-term Long-term Federal Home Loan Bank Advances Weighted-average annualized interest rate Debt, Weighted Average Interest Rate Loss contingency during period Loss Contingency, Loss in Period Number of Shares Subject to Options Unvested, Beginning of Period (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Number of Shares Granted (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross Vested (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested, Number of Shares Forfeited/Canceled (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period Unvested, End of Period (in shares) Weighted Average Grant Date Fair Value Per Share Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract] Unvested, Beginning of Period (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Option, Nonvested, Weighted Average Exercise Price Granted (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value Vested (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested, Weighted Average Grant Date Fair Value Forfeited/Canceled (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period, Weighted Average Exercise Price Unvested, End of Period (in dollars per share) Expected volatility Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate Risk-free interest rate Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate Expected dividends Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate Expected term (years) Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term Weighted average fair value of options granted during period (in dollars per share) Assets and Liabilities Measured at Fair Value on Recurring Basis Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Changes in Level 3 Assets Measured at Fair Value on Recurring Basis Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block] Assets Measured at Fair Value on Nonrecurring Basis Fair Value Measurements, Nonrecurring [Table Text Block] Summary of Significant Unobservable Inputs and Valuation Techniques Fair Value Measurement Inputs and Valuation Techniques [Table Text Block] Estimated Fair Values and Amounts of Financial Instruments Fair Value, by Balance Sheet Grouping [Table Text Block] Number of FHLB stock purchased Federal Home Loan Bank Stock Acquired, Shares Federal Home Loan Bank Stock Acquired, Shares Number of FRBSF stock purchased Purchases of Federal Reserve Bank of San Francisco Stock Purchases of Federal Reserve Bank of San Francisco Stock Number of FHLB stock sold Federal Home Loan Bank Stock Sold, Shares Federal Home Loan Bank Stock Sold, Shares Number of FRBSF stock sold Federal Reserve Bank Of San Francisco Stock Sold, Shares Federal Reserve Bank of San Francisco Stock Sold, Shares Exercise Price Range [Axis] Exercise Price Range [Axis] Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Domain] Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Domain] $2.97 – $3.99 Range One [Member] Range One [Member] $4.00 – $4.99 Range Two [Member] Range Two [Member] $5.00– $5.99 Range Three [Member] Range Three [Member] $6.00– $6.99 Range Five [Member] Range Five [Member] $7.00-$8.90 Range Four [Member] Range Four [Member] Option outstanding, exercise price, lower limit (in dollars per share) Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Lower Range Limit Option outstanding, exercise price, upper limit (in dollars per share) Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Upper Range Limit Options outstanding, vested (in shares) Options outstanding, unvested (in shares) Options outstanding, weighted average exercise price (in dollars per share) Options outstanding, weighted average remaining contractual life (years) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term Options exercisable (in shares) Options exercisable, weighted average exercise price (in dollars per share) Options exercisable, weighted average remaining contractual life Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term Nonrecurring Fair Value, Measurements, Nonrecurring [Member] Other foreclosed assets Other Foreclosed Assets [Member] Other Foreclosed Assets [Member] Other real estate owned Other Real Estate [Member] Other Real Estate [Member] Fair value of assets on nonrecurring basis Financing Receivable Recorded Investment Nonaccrual Status [Table] Financing Receivable Recorded Investment Nonaccrual Status [Table] Financing Receivable Recorded Investment Nonaccrual Status [Table] Consumer Financing Receivable Recorded Investment Nonaccrual Status [Line Items] Financing Receivable Recorded Investment Nonaccrual Status [Line Items] Financing Receivable Recorded Investment Nonaccrual Status [Line Items] Nonaccrual loans Financing Receivable, Recorded Investment, Nonaccrual Status Schedule of Financing Receivables Past Due [Table] Schedule of Financing Receivables Past Due [Table] Financing Receivables, Period Past Due [Axis] Financing Receivables, Period Past Due [Axis] Financing Receivables, Period Past Due [Domain] Financing Receivables, Period Past Due [Domain] 30-59 Days Past Due Financing Receivables, 30 to 59 Days Past Due [Member] 60-89 Days Past Due Financing Receivables, 60 to 89 Days Past Due [Member] 90 Days and Greater Financing Receivables, Equal to Greater than 90 Days Past Due [Member] Financing Receivable, Recorded Investment, Past Due [Line Items] Financing Receivable, Recorded Investment, Past Due [Line Items] Past Due Financing Receivable, Recorded Investment, Past Due Current Financing Receivable, Recorded Investment, Current Loans greater than 90 Days and Accruing Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing Stock-Based Employee Compensation Plans Disclosure of Compensation Related Costs, Share-based Payments [Text Block] Schedule of Short-term Debt [Table] Schedule of Short-term Debt [Table] Short-term Debt, Type [Axis] Short-term Debt, Type [Axis] Short-term Debt, Type [Domain] Short-term Debt, Type [Domain] Other short-term borrowings Other Short-term Borrowings [Member] Other Short-term Borrowings [Member] Short-term Debt [Line Items] Short-term Debt [Line Items] FHLB advances—short-term Long-term Federal Home Loan Bank Advances, Current Other borrowings—short-term Other Short-term Borrowings Total borrowings—short-term Short-term Debt Debt and Capital Lease Obligations Aggregate fair market value of securities pledged as collateral Financial Instruments, Owned and Pledged as Collateral, at Fair Value Payments acquire debt securities Payments to Acquire Debt Securities, Available-for-sale Proceeds from sale of debt securities available for sale Proceeds from Sale of Debt Securities, Available-for-sale Net gain on sale of securities available for sale Gain (Loss) on Sale of Debt Investments Proceeds on the sale of equity security Proceeds From Sale Of Equity Securities, FV-NI Proceeds From Sale Of Equity Securities, FV-NI Loss on sale of equity security Equity Securities, FV-NI, Gain (Loss) Other than temporary impairment on securities available for sale Other-than-temporary Impairment Loss, Debt Securities, Portion Recognized in Earnings Number of investments in limited partnerships Number Of Investments Without Readily Determinable Fair Value Number Of Investments Without Readily Determinable Fair Value Payments to acquire investments Payments to Acquire Investments Estimated Stock Based Compensation Expense for remainder of year 2018 Employee Service Share Based Compensation Unrecognized Compensation Cost Expected To Be Recognized, Remainder of Fiscal Year Employee Service Share Based Compensation Unrecognized Compensation Cost Expected To Be Recognized, Remainder of Fiscal Year Estimated Stock Based Compensation Expense for year 2019 Employee Service Share Based Compensation Unrecognized Compensation Cost Expected To Be Recognized In Year Two Employee Service Share Based Compensation Unrecognized Compensation Cost Expected To Be Recognized In Year Two Estimated Stock Based Compensation Expense for year 2020 Employee Service Share Based Compensation Unrecognized Compensation Cost Expected To Be Recognized In Year Three Employee Service Share Based Compensation Unrecognized Compensation Cost Expected To Be Recognized In Year Three Estimated Stock Based Compensation Expense for year 2021 Employee Service Share Based Compensation Unrecognized Compensation Cost Expected To Be Recognized In Year Four Employee Service Share Based Compensation Unrecognized Compensation Cost Expected To Be Recognized In Year Four Estimated Stock Based Compensation Expense for year 2022 and Beyond Employee Service Share Based Compensation Unrecognized Compensation Cost Expected To Be Recognized In Year Five and Thereafter Employee Service Share Based Compensation Unrecognized Compensation Cost Expected To Be Recognized In Year Five and Thereafter Estimated Stock Based Compensation Expense Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized Commercial real estate - owner occupied and commercial real estate - all other loans Commercial Real Estate, Owner Occupied and Commercial Real Estate, All Other [Member] Commercial Real Estate, Owner Occupied and Commercial Real Estate, All Other [Member] Loans pledged to secure borrowings obtained from the FHLB Loans Pledged as Collateral Loans and leases receivable sold Loans And Leases Receivable, Loans Sold Loans And Leases Receivable, Loans Sold Loans and leases receivable purchased Loans and Leases Receivable, Significant Purchases Loans and Leases Receivable, Significant Purchases Period of loan loss history and industry loss factors used to determine historical losses Loans and Leases Receivable, Allowance, Length of Historical and Industry Loss Factors Loans and Leases Receivable, Allowance, Length of Historical and Industry Loss Factors Loans greater than 90 Days and accruing Impaired loans with no specific reserves Impaired loans, impaired in prior year Impaired Financing Receivable, with No Related Allowance, Recorded Investment, Impaired Prior Year Impaired Financing Receivable, with No Related Allowance, Recorded Investment, Impaired Prior Year Interest that would have been earned had impaired loans remained current in accordance with original terms Loans and Leases Receivable, Impaired, Interest Lost on Nonaccrual Loans Troubled debt restructurings, totals Financing Receivable, Modifications, Recorded Investment Accumulated Other Comprehensive Income (Loss) [Table] Accumulated Other Comprehensive Income (Loss) [Table] Unrealized Gain (Loss) on Securities Available-for-Sale, net of tax Accumulated Net Investment Gain (Loss) Attributable to Parent [Member] Accumulated Other Comprehensive Income (Loss), Net Accumulated Other Comprehensive Income (Loss) [Line Items] Accumulated Other Comprehensive Income (Loss) [Line Items] Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward] AOCI Attributable to Parent, Net of Tax [Roll Forward] Other comprehensive income before reclassifications, net of tax Other Comprehensive Income (Loss), before Reclassifications, Net of Tax Amounts reclassified from accumulated other comprehensive income (loss), net of tax Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax Other comprehensive income, net of tax Other comprehensive income before reclassifications, tax provision Other Comprehensive Income (Loss) before Reclassifications, Tax Other comprehensive loss, tax Other Comprehensive Income (Loss), Tax Available-for-sale Debt Securities [Abstract] Debt Securities, Available-for-sale [Abstract] Amortized Cost Debt Securities, Available-for-sale, Amortized Cost Gross Unrealized Gain Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax Gross Unrealized Loss Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax Estimated Fair Value Amortized Cost Available-for-sale Securities, Amortized Cost Basis Gross Unrealized Gain Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax Gross Unrealized Loss Estimated Fair Value Computation of Basic and Diluted Earnings Per Share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Antidilutive Securities Excluded from Earnings Per Share Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block]