Allowance for Credit Losses - Collateral Dependent Loans by Class of Loan (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Financing Receivable, Credit Quality Indicator [Line Items]
Loans held for investment, outstanding balance	$ 6,963,911	$ 6,999,990
Real Estate
Financing Receivable, Credit Quality Indicator [Line Items]
Loans held for investment, outstanding balance	25,477	34,456
Business Assets
Financing Receivable, Credit Quality Indicator [Line Items]
Loans held for investment, outstanding balance	2,258	6,541
Investment/Cash
Financing Receivable, Credit Quality Indicator [Line Items]
Loans held for investment, outstanding balance	0	0
Other
Financing Receivable, Credit Quality Indicator [Line Items]
Loans held for investment, outstanding balance	10,910	10,473
Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Loans held for investment, outstanding balance	5,331,863	5,406,584
Commercial | Commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Loans held for investment, outstanding balance	2,705,799	2,690,528
Commercial | Commercial real estate | Real Estate
Financing Receivable, Credit Quality Indicator [Line Items]
Loans held for investment, outstanding balance	21,058	28,046
Commercial | Commercial real estate | Business Assets
Financing Receivable, Credit Quality Indicator [Line Items]
Loans held for investment, outstanding balance	0	0
Commercial | Commercial real estate | Investment/Cash
Financing Receivable, Credit Quality Indicator [Line Items]
Loans held for investment, outstanding balance	0	0
Commercial | Commercial real estate | Other
Financing Receivable, Credit Quality Indicator [Line Items]
Loans held for investment, outstanding balance	571	0
Commercial | Commercial and industrial
Financing Receivable, Credit Quality Indicator [Line Items]
Loans held for investment, outstanding balance	1,458,506	1,513,523
Commercial | Commercial and industrial | Real Estate
Financing Receivable, Credit Quality Indicator [Line Items]
Loans held for investment, outstanding balance	259	259
Commercial | Commercial and industrial | Business Assets
Financing Receivable, Credit Quality Indicator [Line Items]
Loans held for investment, outstanding balance	721	4,905
Commercial | Commercial and industrial | Investment/Cash
Financing Receivable, Credit Quality Indicator [Line Items]
Loans held for investment, outstanding balance	0	0
Commercial | Commercial and industrial | Other
Financing Receivable, Credit Quality Indicator [Line Items]
Loans held for investment, outstanding balance	9,859	10,473
Commercial | Commercial construction
Financing Receivable, Credit Quality Indicator [Line Items]
Loans held for investment, outstanding balance	383,237	424,755
Commercial | Commercial construction | Real Estate
Financing Receivable, Credit Quality Indicator [Line Items]
Loans held for investment, outstanding balance	2,167	4,210
Commercial | Commercial construction | Business Assets
Financing Receivable, Credit Quality Indicator [Line Items]
Loans held for investment, outstanding balance	0	0
Commercial | Commercial construction | Investment/Cash
Financing Receivable, Credit Quality Indicator [Line Items]
Loans held for investment, outstanding balance	0	0
Commercial | Commercial construction | Other
Financing Receivable, Credit Quality Indicator [Line Items]
Loans held for investment, outstanding balance	480	0
Commercial | Business banking
Financing Receivable, Credit Quality Indicator [Line Items]
Loans held for investment, outstanding balance	1,141,236	1,135,693
Commercial | Business banking | Real Estate
Financing Receivable, Credit Quality Indicator [Line Items]
Loans held for investment, outstanding balance	1,028	910
Commercial | Business banking | Business Assets
Financing Receivable, Credit Quality Indicator [Line Items]
Loans held for investment, outstanding balance	1,537	1,636
Commercial | Business banking | Investment/Cash
Financing Receivable, Credit Quality Indicator [Line Items]
Loans held for investment, outstanding balance	0	0
Commercial | Business banking | Other
Financing Receivable, Credit Quality Indicator [Line Items]
Loans held for investment, outstanding balance	0	0
Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Loans held for investment, outstanding balance	1,632,048	1,593,406
Consumer | Business banking
Financing Receivable, Credit Quality Indicator [Line Items]
Loans held for investment, outstanding balance		357,900
Consumer | Consumer real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Loans held for investment, outstanding balance	1,162,857	1,127,585
Consumer | Consumer real estate | Real Estate
Financing Receivable, Credit Quality Indicator [Line Items]
Loans held for investment, outstanding balance	965	1,031
Consumer | Consumer real estate | Business Assets
Financing Receivable, Credit Quality Indicator [Line Items]
Loans held for investment, outstanding balance	0	0
Consumer | Consumer real estate | Investment/Cash
Financing Receivable, Credit Quality Indicator [Line Items]
Loans held for investment, outstanding balance	0	0
Consumer | Consumer real estate | Other
Financing Receivable, Credit Quality Indicator [Line Items]
Loans held for investment, outstanding balance	$ 0	$ 0