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, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Loans held-for-investment
Fair Value, Assets Measured on a Nonrecurring Basis
Increase (decrease) in value of assets	$ (9,432)	$ (9,181)	$ (25,674)	$ (28,414)
Investments in tax credit and other investments, net
Fair Value, Assets Measured on a Nonrecurring Basis
Increase (decrease) in value of assets	877	(733)	877	(583)
Other nonperforming assets
Fair Value, Assets Measured on a Nonrecurring Basis
Increase (decrease) in value of assets	0	0	(3,890)	0
OREO
Fair Value, Assets Measured on a Nonrecurring Basis
Increase (decrease) in value of assets	(910)	0	(910)	0
Commercial lending | Loans held-for-investment
Fair Value, Assets Measured on a Nonrecurring Basis
Increase (decrease) in value of assets	(6,944)	(9,117)	(23,152)	(30,648)
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	(6,462)	(8,846)	(15,530)	(30,372)
Commercial lending | Commercial real estate (“CRE”) | Loans held-for-investment
Fair Value, Assets Measured on a Nonrecurring Basis
Increase (decrease) in value of assets	(275)	(271)	(7,336)	(276)
Commercial lending | Multifamily residential | Loans held-for-investment
Fair Value, Assets Measured on a Nonrecurring Basis
Increase (decrease) in value of assets	2	0	(6)	0
Commercial lending | Construction and land | Loans held-for-investment
Fair Value, Assets Measured on a Nonrecurring Basis
Increase (decrease) in value of assets	(209)	0	(280)	0
Consumer lending | Loans held-for-investment
Fair Value, Assets Measured on a Nonrecurring Basis
Increase (decrease) in value of assets	(2,488)	(64)	(2,522)	2,234
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	(8)	0
Consumer lending | HELOCs | Loans held-for-investment
Fair Value, Assets Measured on a Nonrecurring Basis
Increase (decrease) in value of assets	3	(64)	(23)	(257)
Consumer lending | Other consumer | Loans held-for-investment
Fair Value, Assets Measured on a Nonrecurring Basis
Increase (decrease) in value of assets	$ (2,491)	$ 0	$ (2,491)	$ 2,491