Fair Value Measurement and Fair Value of Financial Instruments - Increase (Decrease) in Fair Value of Assets Measured on a Nonrecurring Basis (Details) - Fair Value, Measurements, Nonrecurring - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Loans held-for-investment
Fair Value, Assets Measured on a Nonrecurring Basis
Increase (decrease) in value of assets	$ (6,513)	$ (9,432)	$ (12,333)	$ (25,674)
Tax credit investments
Fair Value, Assets Measured on a Nonrecurring Basis
Increase (decrease) in value of assets	0	877	0	877
OREO
Fair Value, Assets Measured on a Nonrecurring Basis
Increase (decrease) in value of assets	0	(910)	0	(910)
Other nonperforming assets
Fair Value, Assets Measured on a Nonrecurring Basis
Increase (decrease) in value of assets	(6,861)	0	(6,861)	(3,890)
Commercial lending | Loans held-for-investment
Fair Value, Assets Measured on a Nonrecurring Basis
Increase (decrease) in value of assets	(6,595)	(6,944)	(12,418)	(23,152)
Commercial lending | Commercial and industrial (“C&I”) | Loans held-for-investment
Fair Value, Assets Measured on a Nonrecurring Basis
Increase (decrease) in value of assets	(6,054)	(6,462)	(14,740)	(15,530)
Commercial lending | Commercial real estate (“CRE”) | Loans held-for-investment
Fair Value, Assets Measured on a Nonrecurring Basis
Increase (decrease) in value of assets	(533)	(275)	2,330	(7,336)
Commercial lending | Multifamily residential | Loans held-for-investment
Fair Value, Assets Measured on a Nonrecurring Basis
Increase (decrease) in value of assets	(8)	2	(8)	(6)
Commercial lending | Construction and land | Loans held-for-investment
Fair Value, Assets Measured on a Nonrecurring Basis
Increase (decrease) in value of assets	0	(209)	0	(280)
Consumer lending | Loans held-for-investment
Fair Value, Assets Measured on a Nonrecurring Basis
Increase (decrease) in value of assets	82	(2,488)	85	(2,522)
Consumer lending | Single Family Residential | Loans held-for-investment
Fair Value, Assets Measured on a Nonrecurring Basis
Increase (decrease) in value of assets	0	0	0	(8)
Consumer lending | HELOCs | Loans held-for-investment
Fair Value, Assets Measured on a Nonrecurring Basis
Increase (decrease) in value of assets	82	3	85	(23)
Consumer lending | Other consumer | Loans held-for-investment
Fair Value, Assets Measured on a Nonrecurring Basis
Increase (decrease) in value of assets	$ 0	$ (2,491)	$ 0	$ (2,491)