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		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Loans held-for-investment
Fair Value, Assets Measured on a Nonrecurring Basis
Increase (decrease) in value of assets	$ (5,064)	$ (24,940)	$ (23,273)	$ (36,834)
Investments in tax credit and other investments, net
Fair Value, Assets Measured on a Nonrecurring Basis
Increase (decrease) in value of assets	0	0	877	(583)
Other nonperforming assets
Fair Value, Assets Measured on a Nonrecurring Basis
Increase (decrease) in value of assets	(43)	0	(3,933)	0
Commercial lending | Loans held-for-investment
Fair Value, Assets Measured on a Nonrecurring Basis
Increase (decrease) in value of assets	(5,067)	(24,943)	(20,776)	(39,147)
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	(4,977)	(24,928)	(13,590)	(38,855)
Commercial lending | Commercial real estate (“CRE”) | Loans held-for-investment
Fair Value, Assets Measured on a Nonrecurring Basis
Increase (decrease) in value of assets	(106)	(15)	(7,186)	(292)
Commercial lending | Multifamily residential | Loans held-for-investment
Fair Value, Assets Measured on a Nonrecurring Basis
Increase (decrease) in value of assets	16	0	0	0
Consumer lending | Loans held-for-investment
Fair Value, Assets Measured on a Nonrecurring Basis
Increase (decrease) in value of assets	3	3	(2,497)	2,313
Consumer lending | HELOCs | Loans held-for-investment
Fair Value, Assets Measured on a Nonrecurring Basis
Increase (decrease) in value of assets	3	3	(6)	(178)
Consumer lending | Other consumer | Loans held-for-investment
Fair Value, Assets Measured on a Nonrecurring Basis
Increase (decrease) in value of assets	$ 0	$ 0	$ (2,491)	$ 2,491