Allowance for Credit Losses - Allocation of Allowance for Loan and Lease Losses (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Allocation of allowance as well as the activity in allowance
Beginning ACL Balance	$ 197,752	$ 268,018
Charge-offs	(2,299)	(1,952)
Recoveries	1,853	618
Provision for Credit Losses	211	315
Ending ACL Balance	197,517	266,999
Investor loans secured by real estate | CRE non-owner-occupied
Allocation of allowance as well as the activity in allowance
Beginning ACL Balance	37,380	49,176
Charge-offs	0	(154)
Recoveries	0	0
Provision for Credit Losses	(1,406)	(3,477)
Ending ACL Balance	35,974	45,545
Investor loans secured by real estate | Multifamily
Allocation of allowance as well as the activity in allowance
Beginning ACL Balance	55,209	62,534
Charge-offs	0	0
Recoveries	0	0
Provision for Credit Losses	(884)	17,281
Ending ACL Balance	54,325	79,815
Investor loans secured by real estate | Construction and land
Allocation of allowance as well as the activity in allowance
Beginning ACL Balance	5,211	12,435
Charge-offs	0	0
Recoveries	0	0
Provision for Credit Losses	8	828
Ending ACL Balance	5,219	13,263
Investor loans secured by real estate | SBA secured by real estate
Allocation of allowance as well as the activity in allowance
Beginning ACL Balance	3,201	5,159
Charge-offs	(70)	(265)
Recoveries	0	0
Provision for Credit Losses	(81)	247
Ending ACL Balance	3,050	5,141
Business loans secured by real estate | SBA secured by real estate
Allocation of allowance as well as the activity in allowance
Beginning ACL Balance	4,866	6,567
Charge-offs	0	(98)
Recoveries	0	0
Provision for Credit Losses	329	(18)
Ending ACL Balance	5,195	6,451
Business loans secured by real estate | CRE owner-occupied
Allocation of allowance as well as the activity in allowance
Beginning ACL Balance	29,575	50,517
Charge-offs	0	0
Recoveries	10	15
Provision for Credit Losses	2,306	(8,938)
Ending ACL Balance	31,891	41,594
Business loans secured by real estate | Franchise real estate secured
Allocation of allowance as well as the activity in allowance
Beginning ACL Balance	7,985	11,451
Charge-offs	0	0
Recoveries	0	0
Provision for Credit Losses	(8)	(575)
Ending ACL Balance	7,977	10,876
Commercial loans | Commercial and industrial
Allocation of allowance as well as the activity in allowance
Beginning ACL Balance	38,136	46,964
Charge-offs	(2,179)	(1,279)
Recoveries	1,841	601
Provision for Credit Losses	800	(2,913)
Ending ACL Balance	38,598	43,373
Commercial loans | Franchise non-real estate secured
Allocation of allowance as well as the activity in allowance
Beginning ACL Balance	15,084	20,525
Charge-offs	0	(156)
Recoveries	0	0
Provision for Credit Losses	(780)	(1,466)
Ending ACL Balance	14,304	18,903
Commercial loans | SBA non-real estate secured
Allocation of allowance as well as the activity in allowance
Beginning ACL Balance	565	995
Charge-offs	(50)	0
Recoveries	2	2
Provision for Credit Losses	(27)	(107)
Ending ACL Balance	490	890
Retail loans | Single family residential
Allocation of allowance as well as the activity in allowance
Beginning ACL Balance	255	1,204
Charge-offs	0	0
Recoveries	0	0
Provision for Credit Losses	(22)	(382)
Ending ACL Balance	233	822
Retail loans | Consumer
Allocation of allowance as well as the activity in allowance
Beginning ACL Balance	285	491
Charge-offs	0	0
Recoveries	0	0
Provision for Credit Losses	(24)	(165)
Ending ACL Balance	$ 261	$ 326