Loans and Leases - Narrative (Details)	3 Months Ended		22 Months Ended
	Mar. 31, 2022 USD ($) contract	Mar. 31, 2021 USD ($) contract	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans and leases	$ 66,538,000	$ 67,652,000	$ 61,174,000
Allowance for Loan and Lease Losses, Period Increase (Decrease)	(3,200,000)
Provision	(2,000,000)	(53,000,000)
Gross loans and leases held for investment	24,439,749,000		23,026,308,000
Loans and Leases Receivable, Allowance	197,398,000	292,445,000	200,564,000	$ 348,181,000
Loans held for investment, net	$ 24,352,072,000	$ 18,979,228,000	22,941,548,000
Number of loans | contract	14	20
Pre-Modification Outstanding Recorded Investment	$ 1,378,000	$ 38,188,000
Real Estate Mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans and leases	49,534,000	48,907,000	39,832,000
Provision	(11,333,000)	2,603,000
Gross loans and leases held for investment	12,052,868,000		11,189,278,000
Loans and Leases Receivable, Allowance	86,715,000	141,122,000	98,053,000	138,342,000
Loans held for investment, net	12,039,291,000	7,987,213,000	11,178,720,000
Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans and leases	10,402,000	17,471,000	16,213,000
Provision	9,436,000	(45,810,000)
Gross loans and leases held for investment	8,133,779,000		7,888,068,000
Loans and Leases Receivable, Allowance	57,056,000	78,716,000	48,718,000	$ 126,403,000
Loans held for investment, net	8,114,695,000	$ 7,085,840,000	7,868,051,000
Residential Real Estate [Member] | Real Estate Mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans and leases	$ 17,463,000		12,292,000
Number of Loans | contract	1
Financing Receivable, Troubled Debt Restructuring, Subsequent Default	$ 163,000
Loans held for investment, net	$ 8,369,550,000		7,416,421,000
Number of loans | contract	1	2
Pre-Modification Outstanding Recorded Investment	$ 304,000	$ 266,000
Finance Receivable, Payroll Protection Program Loan [Member] | Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for investment, net	70,400,000
Credit Concentration Risk
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans and leases	$ 21,600,000
Credit Concentration Risk | Nonaccrual Loans And Leases Benchmark | Fair Value, Concentration of Risk, All Financial Instruments
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage of nonaccrual loans and leases	32.00%
Nonaccrual
Accounts, Notes, Loans and Financing Receivable [Line Items]
Receivable, 90 or more days past due	$ 18,100,000		18,500,000
Receivable, 30-89 days past due	7,400,000		6,300,000
Financing receivable, nonaccrual status, current	$ 41,100,000		36,400,000
Payment Protection Program 2020 to 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Proceeds from Loan Originations			1,650,000,000
Other Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans | contract	2	1
Financing Receivable, Troubled Debt Restructuring, Subsequent Default	$ 78,000	$ 87,000
Other Commercial | Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans and leases	5,420,000		11,950,000
Loans held for investment, net	$ 1,298,136,000		1,471,981,000
Number of loans | contract	13	12
Pre-Modification Outstanding Recorded Investment	$ 1,074,000	$ 32,250,000
Venture Capital Loans | Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans and leases	3,659,000		2,799,000
Loans held for investment, net	$ 2,077,339,000		2,320,593,000
Number of loans | contract	0	3
Pre-Modification Outstanding Recorded Investment	$ 0	$ 4,502,000
Asset-based | Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans and leases	1,323,000		1,464,000
Loans held for investment, net	$ 4,739,220,000		$ 4,075,477,000
Number of loans | contract	0	1
Pre-Modification Outstanding Recorded Investment	$ 0	$ 503,000