Loans Held for Investment - Internal Risk Grading System under ASC 326 (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	$ 3,033,849	$ 4,696,852
Fiscal Year before Current Fiscal Year	4,237,198	1,736,838
Two Years before Current Fiscal Year	1,402,650	2,322,876
Three Years before Current Fiscal Year	1,788,312	1,254,797
Four Years before Current Fiscal Year	861,690	1,143,567
Prior	2,206,015	2,014,563
Revolving	1,203,904	1,121,488
Revolving Converted to Term During the Period	4,606	4,916
Total	14,676,298	14,295,897
Loans held for investment before basis adjustment	14,738,224
Basis adjustment associated with fair value hedge
Financing Receivable, Credit Quality Indicator [Line Items]
Loans held for investment before basis adjustment	14,738,224	14,295,897
Basis adjustment associated with fair value hedge	(61,926)	0
Investor loans secured by real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	1,948,392	3,088,930
Fiscal Year before Current Fiscal Year	2,954,826	1,320,289
Two Years before Current Fiscal Year	1,034,449	1,681,360
Three Years before Current Fiscal Year	1,268,038	865,841
Four Years before Current Fiscal Year	590,859	717,023
Prior	1,416,489	1,304,033
Revolving	0	10,152
Revolving Converted to Term During the Period	463	0
Total	9,213,516	8,987,628
Investor loans secured by real estate | CRE non-owner-occupied
Financing Receivable, Credit Quality Indicator [Line Items]
Total	2,660,321	2,771,137
Investor loans secured by real estate | CRE non-owner-occupied | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	523,895	708,560
Fiscal Year before Current Fiscal Year	607,153	269,944
Two Years before Current Fiscal Year	208,760	393,097
Three Years before Current Fiscal Year	347,889	387,923
Four Years before Current Fiscal Year	308,317	218,388
Prior	651,593	730,736
Revolving	0	9,353
Revolving Converted to Term During the Period	0	0
Total	2,647,607	2,718,001
Investor loans secured by real estate | CRE non-owner-occupied | Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	0	0
Fiscal Year before Current Fiscal Year	0	0
Two Years before Current Fiscal Year	0	16,166
Three Years before Current Fiscal Year	0	7,682
Four Years before Current Fiscal Year	7,487	0
Prior	0	0
Revolving	0	0
Revolving Converted to Term During the Period	0	0
Total	7,487	23,848
Investor loans secured by real estate | CRE non-owner-occupied | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	0	0
Fiscal Year before Current Fiscal Year	0	0
Two Years before Current Fiscal Year	0	25,777
Three Years before Current Fiscal Year	0	0
Four Years before Current Fiscal Year	194	0
Prior	4,570	2,998
Revolving	0	513
Revolving Converted to Term During the Period	463	0
Total	5,227	29,288
Investor loans secured by real estate | Multifamily
Financing Receivable, Credit Quality Indicator [Line Items]
Total	6,112,026	5,891,934
Investor loans secured by real estate | Multifamily | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	1,230,359	2,260,708
Fiscal Year before Current Fiscal Year	2,187,255	952,127
Two Years before Current Fiscal Year	786,436	1,199,505
Three Years before Current Fiscal Year	889,737	444,904
Four Years before Current Fiscal Year	263,241	479,029
Prior	732,808	554,067
Revolving	0	286
Revolving Converted to Term During the Period	0	0
Total	6,089,836	5,890,626
Investor loans secured by real estate | Multifamily | Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	0
Fiscal Year before Current Fiscal Year	0
Two Years before Current Fiscal Year	0
Three Years before Current Fiscal Year	12,667
Four Years before Current Fiscal Year	0
Prior	0
Revolving	0
Revolving Converted to Term During the Period	0
Total	12,667
Investor loans secured by real estate | Multifamily | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	0	0
Fiscal Year before Current Fiscal Year	6,057	0
Two Years before Current Fiscal Year	0	0
Three Years before Current Fiscal Year	2,723	543
Four Years before Current Fiscal Year	0	0
Prior	743	765
Revolving	0	0
Revolving Converted to Term During the Period	0	0
Total	9,523	1,308
Investor loans secured by real estate | Construction and land
Financing Receivable, Credit Quality Indicator [Line Items]
Total	399,034	277,640
Investor loans secured by real estate | Construction and land | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	187,567	119,532
Fiscal Year before Current Fiscal Year	154,231	97,721
Two Years before Current Fiscal Year	38,760	40,556
Three Years before Current Fiscal Year	9,615	12,415
Four Years before Current Fiscal Year	1,843	3,857
Prior	7,018	3,559
Revolving	0	0
Revolving Converted to Term During the Period	0	0
Total	399,034	277,640
Investor loans secured by real estate | SBA secured by real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Total	42,135	46,917
Investor loans secured by real estate | SBA secured by real estate | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	6,571	130
Fiscal Year before Current Fiscal Year	130	497
Two Years before Current Fiscal Year	493	6,259
Three Years before Current Fiscal Year	5,407	9,074
Four Years before Current Fiscal Year	7,361	12,070
Prior	13,199	9,198
Revolving	0	0
Revolving Converted to Term During the Period	0	0
Total	33,161	37,228
Investor loans secured by real estate | SBA secured by real estate | Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year		0
Fiscal Year before Current Fiscal Year		0
Two Years before Current Fiscal Year		0
Three Years before Current Fiscal Year		957
Four Years before Current Fiscal Year		0
Prior		544
Revolving		0
Revolving Converted to Term During the Period		0
Total		1,501
Investor loans secured by real estate | SBA secured by real estate | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	0	0
Fiscal Year before Current Fiscal Year	0	0
Two Years before Current Fiscal Year	0	0
Three Years before Current Fiscal Year	0	2,343
Four Years before Current Fiscal Year	2,416	3,679
Prior	6,558	2,166
Revolving	0	0
Revolving Converted to Term During the Period	0	0
Total	8,974	8,188
Business loans secured by real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	676,516	1,015,804
Fiscal Year before Current Fiscal Year	873,443	312,168
Two Years before Current Fiscal Year	289,937	352,224
Three Years before Current Fiscal Year	299,206	218,944
Four Years before Current Fiscal Year	158,541	259,808
Prior	568,284	533,240
Revolving	5,661	8,099
Revolving Converted to Term During the Period	0	292
Total	2,871,588	2,700,579
Business loans secured by real estate | SBA secured by real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Total	61,368	69,184
Business loans secured by real estate | SBA secured by real estate | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	10,993	6,379
Fiscal Year before Current Fiscal Year	6,978	2,364
Two Years before Current Fiscal Year	2,329	7,331
Three Years before Current Fiscal Year	5,710	9,125
Four Years before Current Fiscal Year	4,440	10,734
Prior	25,415	24,627
Revolving	0	0
Revolving Converted to Term During the Period	0	0
Total	55,865	60,560
Business loans secured by real estate | SBA secured by real estate | Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	0	0
Fiscal Year before Current Fiscal Year	0	0
Two Years before Current Fiscal Year	0	0
Three Years before Current Fiscal Year	0	0
Four Years before Current Fiscal Year	0	0
Prior	118	62
Revolving	0	0
Revolving Converted to Term During the Period	0	0
Total	118	62
Business loans secured by real estate | SBA secured by real estate | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	0	0
Fiscal Year before Current Fiscal Year	0	0
Two Years before Current Fiscal Year	0	0
Three Years before Current Fiscal Year	0	2,062
Four Years before Current Fiscal Year	1,354	2,690
Prior	4,031	3,810
Revolving	0	0
Revolving Converted to Term During the Period	0	0
Total	5,385	8,562
Business loans secured by real estate | CRE owner-occupied
Financing Receivable, Credit Quality Indicator [Line Items]
Total	2,432,163	2,251,014
Business loans secured by real estate | CRE owner-occupied | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	593,826	853,044
Fiscal Year before Current Fiscal Year	718,223	273,469
Two Years before Current Fiscal Year	242,125	287,249
Three Years before Current Fiscal Year	240,772	161,636
Four Years before Current Fiscal Year	114,581	187,130
Prior	448,531	464,271
Revolving	5,661	6,738
Revolving Converted to Term During the Period	0	292
Total	2,363,719	2,233,829
Business loans secured by real estate | CRE owner-occupied | Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	334
Fiscal Year before Current Fiscal Year	1,015
Two Years before Current Fiscal Year	0
Three Years before Current Fiscal Year	0
Four Years before Current Fiscal Year	675
Prior	327
Revolving	0
Revolving Converted to Term During the Period	0
Total	2,351
Business loans secured by real estate | CRE owner-occupied | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	10,838	0
Fiscal Year before Current Fiscal Year	2,541	0
Two Years before Current Fiscal Year	11,970	2,553
Three Years before Current Fiscal Year	2,403	6,074
Four Years before Current Fiscal Year	4,676	2,966
Prior	33,665	5,592
Revolving	0	0
Revolving Converted to Term During the Period	0	0
Total	66,093	17,185
Business loans secured by real estate | Franchise real estate secured
Financing Receivable, Credit Quality Indicator [Line Items]
Total	378,057	380,381
Business loans secured by real estate | Franchise real estate secured | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	54,654	156,381
Fiscal Year before Current Fiscal Year	131,541	36,335
Two Years before Current Fiscal Year	33,513	55,091
Three Years before Current Fiscal Year	44,229	40,047
Four Years before Current Fiscal Year	32,815	56,288
Prior	55,893	34,878
Revolving	0	1,361
Revolving Converted to Term During the Period	0	0
Total	352,645	380,381
Business loans secured by real estate | Franchise real estate secured | Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	4,891
Fiscal Year before Current Fiscal Year	13,145
Two Years before Current Fiscal Year	0
Three Years before Current Fiscal Year	0
Four Years before Current Fiscal Year	0
Prior	0
Revolving	0
Revolving Converted to Term During the Period	0
Total	18,036
Business loans secured by real estate | Franchise real estate secured | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	980
Fiscal Year before Current Fiscal Year	0
Two Years before Current Fiscal Year	0
Three Years before Current Fiscal Year	6,092
Four Years before Current Fiscal Year	0
Prior	304
Revolving	0
Revolving Converted to Term During the Period	0
Total	7,376
Commercial loans
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	408,941	591,794
Fiscal Year before Current Fiscal Year	408,923	104,142
Two Years before Current Fiscal Year	78,071	289,238
Three Years before Current Fiscal Year	221,057	169,961
Four Years before Current Fiscal Year	112,268	164,717
Prior	170,512	107,053
Revolving	1,172,924	1,075,204
Revolving Converted to Term During the Period	4,143	4,624
Total	2,576,839	2,506,733
Commercial loans | Commercial and industrial
Financing Receivable, Credit Quality Indicator [Line Items]
Total	2,160,948	2,103,112
Commercial loans | Commercial and industrial | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	282,131	425,683
Fiscal Year before Current Fiscal Year	262,044	79,635
Two Years before Current Fiscal Year	55,659	200,234
Three Years before Current Fiscal Year	155,310	117,471
Four Years before Current Fiscal Year	78,684	123,345
Prior	121,918	70,789
Revolving	1,134,568	1,032,053
Revolving Converted to Term During the Period	3,412	3,371
Total	2,093,726	2,052,581
Commercial loans | Commercial and industrial | Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	15,105	0
Fiscal Year before Current Fiscal Year	3,567	0
Two Years before Current Fiscal Year	798	146
Three Years before Current Fiscal Year	0	0
Four Years before Current Fiscal Year	1,864	0
Prior	41	152
Revolving	9,898	14,814
Revolving Converted to Term During the Period	0	178
Total	31,273	15,290
Commercial loans | Commercial and industrial | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	2,590	1,772
Fiscal Year before Current Fiscal Year	80	0
Two Years before Current Fiscal Year	0	14
Three Years before Current Fiscal Year	3,867	2,683
Four Years before Current Fiscal Year	562	863
Prior	1,029	1,150
Revolving	27,680	27,684
Revolving Converted to Term During the Period	141	1,075
Total	35,949	35,241
Commercial loans | Franchise non-real estate secured
Financing Receivable, Credit Quality Indicator [Line Items]
Total	404,791	392,576
Commercial loans | Franchise non-real estate secured | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	102,542	163,865
Fiscal Year before Current Fiscal Year	128,030	23,943
Two Years before Current Fiscal Year	18,486	85,206
Three Years before Current Fiscal Year	46,027	45,061
Four Years before Current Fiscal Year	28,664	23,672
Prior	43,486	31,163
Revolving	778	0
Revolving Converted to Term During the Period	0	0
Total	368,013	372,910
Commercial loans | Franchise non-real estate secured | Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	1,372
Fiscal Year before Current Fiscal Year	14,382
Two Years before Current Fiscal Year	0
Three Years before Current Fiscal Year	11,829
Four Years before Current Fiscal Year	0
Prior	0
Revolving	0
Revolving Converted to Term During the Period	0
Total	27,583
Commercial loans | Franchise non-real estate secured | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	1,757	0
Fiscal Year before Current Fiscal Year	385	0
Two Years before Current Fiscal Year	2,852	1,589
Three Years before Current Fiscal Year	2,256	3,627
Four Years before Current Fiscal Year	1,637	13,346
Prior	308	1,104
Revolving	0	0
Revolving Converted to Term During the Period	0	0
Total	9,195	19,666
Commercial loans | SBA non-real estate secured
Financing Receivable, Credit Quality Indicator [Line Items]
Total	11,100	11,045
Commercial loans | SBA non-real estate secured | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	3,444	474
Fiscal Year before Current Fiscal Year	435	564
Two Years before Current Fiscal Year	276	1,292
Three Years before Current Fiscal Year	1,638	666
Four Years before Current Fiscal Year	633	2,806
Prior	3,124	2,148
Revolving	0	0
Revolving Converted to Term During the Period	0	0
Total	9,550	7,950
Commercial loans | SBA non-real estate secured | Special mention
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	0	0
Fiscal Year before Current Fiscal Year	0	0
Two Years before Current Fiscal Year	0	681
Three Years before Current Fiscal Year	0	114
Four Years before Current Fiscal Year	0	0
Prior	0	0
Revolving	0	0
Revolving Converted to Term During the Period	0	0
Total	0	795
Commercial loans | SBA non-real estate secured | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	0	0
Fiscal Year before Current Fiscal Year	0	0
Two Years before Current Fiscal Year	0	76
Three Years before Current Fiscal Year	130	339
Four Years before Current Fiscal Year	224	685
Prior	606	547
Revolving	0	653
Revolving Converted to Term During the Period	590	0
Total	1,550	2,300
Retail loans
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	0	324
Fiscal Year before Current Fiscal Year	6	239
Two Years before Current Fiscal Year	193	54
Three Years before Current Fiscal Year	11	51
Four Years before Current Fiscal Year	22	2,019
Prior	50,730	70,237
Revolving	25,319	28,033
Revolving Converted to Term During the Period	0	0
Total	76,281	100,957
Retail loans | Single family residential
Financing Receivable, Credit Quality Indicator [Line Items]
Total	72,997	95,292
Retail loans | Single family residential | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	0	313
Fiscal Year before Current Fiscal Year	0	211
Two Years before Current Fiscal Year	176	0
Three Years before Current Fiscal Year	0	32
Four Years before Current Fiscal Year	22	2,008
Prior	49,729	68,759
Revolving	23,065	23,920
Revolving Converted to Term During the Period	0	0
Total	72,992	95,243
Retail loans | Single family residential | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	0	0
Fiscal Year before Current Fiscal Year	0	0
Two Years before Current Fiscal Year	0	0
Three Years before Current Fiscal Year	0	0
Four Years before Current Fiscal Year	0	0
Prior	5	49
Revolving	0	0
Revolving Converted to Term During the Period	0	0
Total	5	49
Retail loans | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Total	3,284	5,665
Retail loans | Consumer | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	0	11
Fiscal Year before Current Fiscal Year	6	28
Two Years before Current Fiscal Year	17	49
Three Years before Current Fiscal Year	11	19
Four Years before Current Fiscal Year	0	11
Prior	969	1,394
Revolving	2,254	4,113
Revolving Converted to Term During the Period	0	0
Total	3,257	5,625
Retail loans | Consumer | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Current Fiscal Year	0	0
Fiscal Year before Current Fiscal Year	0	0
Two Years before Current Fiscal Year	0	5
Three Years before Current Fiscal Year	0	0
Four Years before Current Fiscal Year	0	0
Prior	27	35
Revolving	0	0
Revolving Converted to Term During the Period	0	0
Total	$ 27	$ 40