Allowance for Credit Losses - Allocation of Allowance for Credit Losses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Allocation of allowance as well as the activity in allowance
Beginning ACL Balance	$ 268,018	$ 35,698	$ 36,072
Initial ACL Recorded for PCD Loans		21,242
Charge-offs	(8,616)	(19,858)	(7,853)
Recoveries	5,419	2,988	344
Provision for credit losses	(67,069)	172,262	7,135
Ending ACL Balance	197,752	268,018	35,698
Investor loans secured by real estate | CRE non-owner-occupied
Allocation of allowance as well as the activity in allowance
Beginning ACL Balance	49,176	1,899	1,624
Initial ACL Recorded for PCD Loans		3,025
Charge-offs	(154)	(839)	(625)
Recoveries	78	44	0
Provision for credit losses	(11,720)	36,624	900
Ending ACL Balance	37,380	49,176	1,899
Investor loans secured by real estate | Multifamily
Allocation of allowance as well as the activity in allowance
Beginning ACL Balance	62,534	729	740
Initial ACL Recorded for PCD Loans		8,710
Charge-offs	0	0	0
Recoveries	0	0	0
Provision for credit losses	(7,325)	43,921	(11)
Ending ACL Balance	55,209	62,534	729
Investor loans secured by real estate | Construction and land
Allocation of allowance as well as the activity in allowance
Beginning ACL Balance	12,435	4,484	5,964
Initial ACL Recorded for PCD Loans		2,051
Charge-offs	0	(539)	0
Recoveries	0	0	0
Provision for credit losses	(7,224)	6,563	(1,480)
Ending ACL Balance	5,211	12,435	4,484
Investor loans secured by real estate | SBA secured by real estate
Allocation of allowance as well as the activity in allowance
Beginning ACL Balance	5,159	1,915	1,827
Initial ACL Recorded for PCD Loans		0
Charge-offs	(424)	(705)	(742)
Recoveries	3	34	0
Provision for credit losses	(1,537)	5,316	830
Ending ACL Balance	3,201	5,159	1,915
Business loans secured by real estate | SBA secured by real estate
Allocation of allowance as well as the activity in allowance
Beginning ACL Balance	6,567	2,119	1,824
Initial ACL Recorded for PCD Loans		235
Charge-offs	(98)	(338)	(908)
Recoveries	130	147	10
Provision for credit losses	(1,733)	2,197	1,193
Ending ACL Balance	4,866	6,567	2,119
Business loans secured by real estate | CRE owner-occupied
Allocation of allowance as well as the activity in allowance
Beginning ACL Balance	50,517	2,781	1,908
Initial ACL Recorded for PCD Loans		3,766
Charge-offs	0	(1,739)	(125)
Recoveries	56	59	46
Provision for credit losses	(20,998)	25,484	952
Ending ACL Balance	29,575	50,517	2,781
Business loans secured by real estate | Franchise real estate secured
Allocation of allowance as well as the activity in allowance
Beginning ACL Balance	11,451	592	743
Initial ACL Recorded for PCD Loans		0
Charge-offs	0	(932)	(1,377)
Recoveries	0	0	0
Provision for credit losses	(3,466)	6,592	1,226
Ending ACL Balance	7,985	11,451	592
Commercial loans | Commercial and industrial
Allocation of allowance as well as the activity in allowance
Beginning ACL Balance	46,964	13,857	13,695
Initial ACL Recorded for PCD Loans		2,325
Charge-offs	(5,384)	(6,891)	(2,318)
Recoveries	4,720	1,818	189
Provision for credit losses	(8,164)	35,768	2,291
Ending ACL Balance	38,136	46,964	13,857
Commercial loans | Franchise non-real estate secured
Allocation of allowance as well as the activity in allowance
Beginning ACL Balance	20,525	5,816	6,066
Initial ACL Recorded for PCD Loans		0
Charge-offs	(2,554)	(6,731)	(1,154)
Recoveries	405	866	18
Provision for credit losses	(3,292)	11,360	886
Ending ACL Balance	15,084	20,525	5,816
Commercial loans | SBA non-real estate secured
Allocation of allowance as well as the activity in allowance
Beginning ACL Balance	995	445	654
Initial ACL Recorded for PCD Loans		924
Charge-offs	0	(899)	(588)
Recoveries	21	14	68
Provision for credit losses	(451)	293	311
Ending ACL Balance	565	995	445
Retail loans | Single family residential
Allocation of allowance as well as the activity in allowance
Beginning ACL Balance	1,204	655	808
Initial ACL Recorded for PCD Loans		206
Charge-offs	0	(106)	0
Recoveries	3	2	2
Provision for credit losses	(952)	(94)	(155)
Ending ACL Balance	255	1,204	655
Retail loans | Consumer
Allocation of allowance as well as the activity in allowance
Beginning ACL Balance	491	406	219
Initial ACL Recorded for PCD Loans		0
Charge-offs	(2)	(139)	(16)
Recoveries	3	4	11
Provision for credit losses	(207)	(1,762)	192
Ending ACL Balance	$ 285	491	406
Cumulative effect of the change in accounting principle
Allocation of allowance as well as the activity in allowance
Beginning ACL Balance		55,686
Ending ACL Balance			55,686
Cumulative effect of the change in accounting principle | Investor loans secured by real estate | CRE non-owner-occupied
Allocation of allowance as well as the activity in allowance
Beginning ACL Balance		8,423
Ending ACL Balance			8,423
Cumulative effect of the change in accounting principle | Investor loans secured by real estate | Multifamily
Allocation of allowance as well as the activity in allowance
Beginning ACL Balance		9,174
Ending ACL Balance			9,174
Cumulative effect of the change in accounting principle | Investor loans secured by real estate | Construction and land
Allocation of allowance as well as the activity in allowance
Beginning ACL Balance		(124)
Ending ACL Balance			(124)
Cumulative effect of the change in accounting principle | Investor loans secured by real estate | SBA secured by real estate
Allocation of allowance as well as the activity in allowance
Beginning ACL Balance		(1,401)
Ending ACL Balance			(1,401)
Cumulative effect of the change in accounting principle | Business loans secured by real estate | SBA secured by real estate
Allocation of allowance as well as the activity in allowance
Beginning ACL Balance		2,207
Ending ACL Balance			2,207
Cumulative effect of the change in accounting principle | Business loans secured by real estate | CRE owner-occupied
Allocation of allowance as well as the activity in allowance
Beginning ACL Balance		20,166
Ending ACL Balance			20,166
Cumulative effect of the change in accounting principle | Business loans secured by real estate | Franchise real estate secured
Allocation of allowance as well as the activity in allowance
Beginning ACL Balance		5,199
Ending ACL Balance			5,199
Cumulative effect of the change in accounting principle | Commercial loans | Commercial and industrial
Allocation of allowance as well as the activity in allowance
Beginning ACL Balance		87
Ending ACL Balance			87
Cumulative effect of the change in accounting principle | Commercial loans | Franchise non-real estate secured
Allocation of allowance as well as the activity in allowance
Beginning ACL Balance		9,214
Ending ACL Balance			9,214
Cumulative effect of the change in accounting principle | Commercial loans | SBA non-real estate secured
Allocation of allowance as well as the activity in allowance
Beginning ACL Balance		218
Ending ACL Balance			218
Cumulative effect of the change in accounting principle | Retail loans | Single family residential
Allocation of allowance as well as the activity in allowance
Beginning ACL Balance		541
Ending ACL Balance			541
Cumulative effect of the change in accounting principle | Retail loans | Consumer
Allocation of allowance as well as the activity in allowance
Beginning ACL Balance		$ 1,982
Ending ACL Balance			$ 1,982