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
	Mar. 31, 2021	Mar. 31, 2020
Loans held-for-investment
Fair Value, Assets Measured on a Nonrecurring Basis
Increase (decrease) in value of assets	$ (12,495)	$ (19,208)
Investments in tax credit and other investments, net
Fair Value, Assets Measured on a Nonrecurring Basis
Increase (decrease) in value of assets	0	150
Other nonperforming assets
Fair Value, Assets Measured on a Nonrecurring Basis
Increase (decrease) in value of assets	(3,890)	(300)
Commercial lending | Loans held-for-investment
Fair Value, Assets Measured on a Nonrecurring Basis
Increase (decrease) in value of assets	(12,458)	(21,506)
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	(5,309)	(21,501)
Commercial lending | Commercial real estate (“CRE”) | Loans held-for-investment
Fair Value, Assets Measured on a Nonrecurring Basis
Increase (decrease) in value of assets	(7,062)	(5)
Commercial lending | Multifamily residential | Loans held-for-investment
Fair Value, Assets Measured on a Nonrecurring Basis
Increase (decrease) in value of assets	(16)	0
Commercial lending | Construction and land | Loans held-for-investment
Fair Value, Assets Measured on a Nonrecurring Basis
Increase (decrease) in value of assets	(71)	0
Consumer lending | Loans held-for-investment
Fair Value, Assets Measured on a Nonrecurring Basis
Increase (decrease) in value of assets	(37)	2,298
Consumer lending | HELOCs | Loans held-for-investment
Fair Value, Assets Measured on a Nonrecurring Basis
Increase (decrease) in value of assets	(37)	(193)
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