Allowance for Credit Losses - Commercial Real Estate and Commercial Loan Segments (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Financing Receivable, Allowance for Credit Loss [Line Items]
Current Fiscal Year	$ 1,074,728	$ 4,696,852
Fiscal Year before Current Fiscal Year	4,657,598	1,736,838
Two Years before Current Fiscal Year	1,608,350	2,322,876
Three Years before Current Fiscal Year	2,154,680	1,254,797
Four Years before Current Fiscal Year	1,121,305	1,143,567
Prior	2,873,255	2,014,563
Revolving	1,241,092	1,121,488
Revolving Converted to Term During the Period	2,747	4,916
Total	14,733,755	14,295,897
Investor loans secured by real estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Current Fiscal Year	690,589	3,088,930
Fiscal Year before Current Fiscal Year	3,083,122	1,320,289
Two Years before Current Fiscal Year	1,208,893	1,681,360
Three Years before Current Fiscal Year	1,546,339	865,841
Four Years before Current Fiscal Year	775,029	717,023
Prior	1,848,076	1,304,033
Revolving	10,140	10,152
Revolving Converted to Term During the Period	0	0
Total	9,162,188	8,987,628
Investor loans secured by real estate | CRE non-owner-occupied
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	2,774,650	2,771,137
Investor loans secured by real estate | CRE non-owner-occupied | 0% - 5.00%
Financing Receivable, Allowance for Credit Loss [Line Items]
Current Fiscal Year	176,426	654,823
Fiscal Year before Current Fiscal Year	651,475	233,718
Two Years before Current Fiscal Year	250,051	375,691
Three Years before Current Fiscal Year	369,190	392,892
Four Years before Current Fiscal Year	339,561	193,762
Prior	791,623	682,357
Revolving	9,354	4,022
Revolving Converted to Term During the Period	0	0
Total	2,587,680	2,537,265
Investor loans secured by real estate | CRE non-owner-occupied | >5.00% - 10.00%
Financing Receivable, Allowance for Credit Loss [Line Items]
Current Fiscal Year	0	37,931
Fiscal Year before Current Fiscal Year	8,632	22,965
Two Years before Current Fiscal Year	1,141	9,174
Three Years before Current Fiscal Year	718	2,713
Four Years before Current Fiscal Year	16,386	23,559
Prior	54,229	23,707
Revolving	0	5,331
Revolving Converted to Term During the Period	0	0
Total	81,106	125,380
Investor loans secured by real estate | CRE non-owner-occupied | Greater than 10%
Financing Receivable, Allowance for Credit Loss [Line Items]
Current Fiscal Year	0	15,806
Fiscal Year before Current Fiscal Year	10,526	13,261
Two Years before Current Fiscal Year	5,896	50,175
Three Years before Current Fiscal Year	59,354	0
Four Years before Current Fiscal Year	0	1,067
Prior	29,588	27,670
Revolving	500	513
Revolving Converted to Term During the Period	0	0
Total	105,864	108,492
Investor loans secured by real estate | Multifamily
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	6,041,085	5,891,934
Investor loans secured by real estate | Multifamily | 0% - 5.00%
Financing Receivable, Allowance for Credit Loss [Line Items]
Current Fiscal Year	461,776	2,242,420
Fiscal Year before Current Fiscal Year	2,251,232	929,964
Two Years before Current Fiscal Year	865,755	1,174,859
Three Years before Current Fiscal Year	1,057,766	442,410
Four Years before Current Fiscal Year	398,127	470,107
Prior	926,880	548,156
Revolving	286	286
Revolving Converted to Term During the Period	0	0
Total	5,961,822	5,808,202
Investor loans secured by real estate | Multifamily | >5.00% - 10.00%
Financing Receivable, Allowance for Credit Loss [Line Items]
Current Fiscal Year	4,218	13,226
Fiscal Year before Current Fiscal Year	23,077	7,393
Two Years before Current Fiscal Year	5,903	24,646
Three Years before Current Fiscal Year	24,620	1,807
Four Years before Current Fiscal Year	1,799	8,922
Prior	14,581	6,676
Revolving	0	0
Revolving Converted to Term During the Period	0	0
Total	74,198	62,670
Investor loans secured by real estate | Multifamily | Greater than 10%
Financing Receivable, Allowance for Credit Loss [Line Items]
Current Fiscal Year	0	5,062
Fiscal Year before Current Fiscal Year	5,065	14,770
Two Years before Current Fiscal Year	0	0
Three Years before Current Fiscal Year	0	1,230
Four Years before Current Fiscal Year	0	0
Prior	0	0
Revolving	0	0
Revolving Converted to Term During the Period	0	0
Total	5,065	21,062
Investor loans secured by real estate | Construction and land
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	303,811	277,640
Investor loans secured by real estate | Construction and land | 0% - 5.00%
Financing Receivable, Allowance for Credit Loss [Line Items]
Current Fiscal Year	45,018	110,545
Fiscal Year before Current Fiscal Year	106,397	81,029
Two Years before Current Fiscal Year	62,442	23,030
Three Years before Current Fiscal Year	15,840	8,321
Four Years before Current Fiscal Year	5,618	3,857
Prior	7,389	3,559
Revolving	0	0
Revolving Converted to Term During the Period	0	0
Total	242,704	230,341
Investor loans secured by real estate | Construction and land | >5.00% - 10.00%
Financing Receivable, Allowance for Credit Loss [Line Items]
Current Fiscal Year	1,185	5,500
Fiscal Year before Current Fiscal Year	23,088	14,264
Two Years before Current Fiscal Year	13,821	9,931
Three Years before Current Fiscal Year	4,815	4,094
Four Years before Current Fiscal Year	0	0
Prior	0	0
Revolving	0	0
Revolving Converted to Term During the Period	0	0
Total	42,909	33,789
Investor loans secured by real estate | Construction and land | Greater than 10%
Financing Receivable, Allowance for Credit Loss [Line Items]
Current Fiscal Year	0	3,487
Fiscal Year before Current Fiscal Year	3,500	2,428
Two Years before Current Fiscal Year	3,388	7,595
Three Years before Current Fiscal Year	7,901	0
Four Years before Current Fiscal Year	3,409	0
Prior	0	0
Revolving	0	0
Revolving Converted to Term During the Period	0	0
Total	18,198	13,510
Investor loans secured by real estate | SBA secured by real estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	42,642	46,917
Investor loans secured by real estate | SBA secured by real estate | 0% - 5.00%
Financing Receivable, Allowance for Credit Loss [Line Items]
Current Fiscal Year	1,966	130
Fiscal Year before Current Fiscal Year	130	497
Two Years before Current Fiscal Year	496	6,259
Three Years before Current Fiscal Year	6,135	12,374
Four Years before Current Fiscal Year	10,129	15,149
Prior	23,213	11,572
Revolving	0	0
Revolving Converted to Term During the Period	0	0
Total	42,069	45,981
Investor loans secured by real estate | SBA secured by real estate | >5.00% - 10.00%
Financing Receivable, Allowance for Credit Loss [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	0	0
Revolving	0	0
Revolving Converted to Term During the Period	0	0
Total	0	0
Investor loans secured by real estate | SBA secured by real estate | Greater than 10%
Financing Receivable, Allowance for Credit Loss [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	600
Prior	573	336
Revolving	0	0
Revolving Converted to Term During the Period	0	0
Total	573	936
Business loans secured by real estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Current Fiscal Year	281,024	1,015,804
Fiscal Year before Current Fiscal Year	994,405	312,168
Two Years before Current Fiscal Year	306,308	352,224
Three Years before Current Fiscal Year	342,773	218,944
Four Years before Current Fiscal Year	192,883	259,808
Prior	722,605	533,240
Revolving	4,719	8,099
Revolving Converted to Term During the Period	0	292
Total	2,844,717	2,700,579
Business loans secured by real estate | SBA secured by real estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	68,466	69,184
Business loans secured by real estate | SBA secured by real estate | 0% - 5.00%
Financing Receivable, Allowance for Credit Loss [Line Items]
Current Fiscal Year	6,107	6,379
Fiscal Year before Current Fiscal Year	7,452	2,364
Two Years before Current Fiscal Year	1,596	6,040
Three Years before Current Fiscal Year	5,785	8,986
Four Years before Current Fiscal Year	3,459	8,718
Prior	22,774	16,947
Revolving	0	0
Revolving Converted to Term During the Period	0	0
Total	47,173	49,434
Business loans secured by real estate | SBA secured by real estate | >5.00% - 10.00%
Financing Receivable, Allowance for Credit Loss [Line Items]
Current Fiscal Year	0	0
Fiscal Year before Current Fiscal Year	0	0
Two Years before Current Fiscal Year	761	1,291
Three Years before Current Fiscal Year	1,348	139
Four Years before Current Fiscal Year	1,302	2,006
Prior	9,414	7,681
Revolving	0	0
Revolving Converted to Term During the Period	0	0
Total	12,825	11,117
Business loans secured by real estate | SBA secured by real estate | Greater than 10%
Financing Receivable, Allowance for Credit Loss [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	1,887	2,700
Prior	6,581	3,871
Revolving	0	0
Revolving Converted to Term During the Period	0	0
Total	8,468	8,633
Business loans secured by real estate | CRE owner-occupied
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	2,391,984	2,251,014
Business loans secured by real estate | CRE owner-occupied | 0% - 5.00%
Financing Receivable, Allowance for Credit Loss [Line Items]
Current Fiscal Year	250,202	853,044
Fiscal Year before Current Fiscal Year	830,646	273,469
Two Years before Current Fiscal Year	263,304	287,249
Three Years before Current Fiscal Year	279,071	161,635
Four Years before Current Fiscal Year	143,848	187,130
Prior	597,055	456,170
Revolving	4,719	6,738
Revolving Converted to Term During the Period	0	292
Total	2,368,845	2,225,727
Business loans secured by real estate | CRE owner-occupied | >5.00% - 10.00%
Financing Receivable, Allowance for Credit Loss [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	764	0
Prior	0	8,101
Revolving	0	0
Revolving Converted to Term During the Period	0	0
Total	764	8,101
Business loans secured by real estate | CRE owner-occupied | Greater than 10%
Financing Receivable, Allowance for Credit Loss [Line Items]
Current Fiscal Year	0	0
Fiscal Year before Current Fiscal Year	0	0
Two Years before Current Fiscal Year	4,673	2,553
Three Years before Current Fiscal Year	2,516	6,075
Four Years before Current Fiscal Year	5,140	2,966
Prior	10,046	5,592
Revolving	0	0
Revolving Converted to Term During the Period	0	0
Total	22,375	17,186
Business loans secured by real estate | Franchise real estate secured
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	384,267	380,381
Business loans secured by real estate | Franchise real estate secured | 0% - 5.00%
Financing Receivable, Allowance for Credit Loss [Line Items]
Current Fiscal Year	24,715	154,009
Fiscal Year before Current Fiscal Year	152,674	36,335
Two Years before Current Fiscal Year	35,974	55,091
Three Years before Current Fiscal Year	54,053	37,559
Four Years before Current Fiscal Year	35,233	53,519
Prior	73,922	33,635
Revolving	0	1,361
Revolving Converted to Term During the Period	0	0
Total	376,571	371,509
Business loans secured by real estate | Franchise real estate secured | >5.00% - 10.00%
Financing Receivable, Allowance for Credit Loss [Line Items]
Current Fiscal Year	0	843
Fiscal Year before Current Fiscal Year	1,245	0
Two Years before Current Fiscal Year	0	0
Three Years before Current Fiscal Year	0	2,488
Four Years before Current Fiscal Year	1,250	2,769
Prior	2,813	1,243
Revolving	0	0
Revolving Converted to Term During the Period	0	0
Total	5,308	7,343
Business loans secured by real estate | Franchise real estate secured | Greater than 10%
Financing Receivable, Allowance for Credit Loss [Line Items]
Current Fiscal Year	0	1,529
Fiscal Year before Current Fiscal Year	2,388	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	0	0
Revolving	0	0
Revolving Converted to Term During the Period	0	0
Total	2,388	1,529
Commercial loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Current Fiscal Year	103,115	591,794
Fiscal Year before Current Fiscal Year	579,752	104,142
Two Years before Current Fiscal Year	92,930	289,238
Three Years before Current Fiscal Year	265,527	169,961
Four Years before Current Fiscal Year	153,352	164,717
Prior	245,541	107,053
Revolving	1,198,751	1,075,204
Revolving Converted to Term During the Period	2,747	4,624
Total	2,641,715	2,506,733
Commercial loans | Commercial and industrial
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	2,242,632	2,103,112
Commercial loans | Commercial and industrial | 0% - 5.00%
Financing Receivable, Allowance for Credit Loss [Line Items]
Current Fiscal Year	75,796	417,780
Fiscal Year before Current Fiscal Year	410,671	77,755
Two Years before Current Fiscal Year	67,470	192,478
Three Years before Current Fiscal Year	178,211	114,593
Four Years before Current Fiscal Year	101,951	120,869
Prior	177,185	67,194
Revolving	854,129	680,662
Revolving Converted to Term During the Period	1,247	3,380
Total	1,866,660	1,674,711
Commercial loans | Commercial and industrial | >5.00% - 10.00%
Financing Receivable, Allowance for Credit Loss [Line Items]
Current Fiscal Year	2,111	8,349
Fiscal Year before Current Fiscal Year	6,964	1,880
Two Years before Current Fiscal Year	1,608	7,757
Three Years before Current Fiscal Year	7,018	2,878
Four Years before Current Fiscal Year	3,819	2,476
Prior	3,589	3,595
Revolving	317,797	375,829
Revolving Converted to Term During the Period	0	341
Total	342,906	403,105
Commercial loans | Commercial and industrial | Greater than 10%
Financing Receivable, Allowance for Credit Loss [Line Items]
Current Fiscal Year	963	1,326
Fiscal Year before Current Fiscal Year	1,941	0
Two Years before Current Fiscal Year	0	159
Three Years before Current Fiscal Year	12	2,683
Four Years before Current Fiscal Year	1,365	863
Prior	1,763	1,302
Revolving	25,522	18,060
Revolving Converted to Term During the Period	1,500	903
Total	33,066	25,296
Commercial loans | Franchise non-real estate secured
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	388,322	392,576
Commercial loans | Franchise non-real estate secured | 0% - 5.00%
Financing Receivable, Allowance for Credit Loss [Line Items]
Current Fiscal Year	23,120	155,064
Fiscal Year before Current Fiscal Year	158,940	18,370
Two Years before Current Fiscal Year	15,289	64,503
Three Years before Current Fiscal Year	62,490	39,389
Four Years before Current Fiscal Year	36,456	21,483
Prior	35,717	21,524
Revolving	555	0
Revolving Converted to Term During the Period	0	0
Total	332,567	320,333
Commercial loans | Franchise non-real estate secured | >5.00% - 10.00%
Financing Receivable, Allowance for Credit Loss [Line Items]
Current Fiscal Year	462	8,801
Fiscal Year before Current Fiscal Year	769	5,573
Two Years before Current Fiscal Year	8,020	20,703
Three Years before Current Fiscal Year	14,244	5,672
Four Years before Current Fiscal Year	5,244	2,189
Prior	7,306	8,840
Revolving	106	0
Revolving Converted to Term During the Period	0	0
Total	36,151	51,778
Commercial loans | Franchise non-real estate secured | Greater than 10%
Financing Receivable, Allowance for Credit Loss [Line Items]
Current Fiscal Year	0	0
Fiscal Year before Current Fiscal Year	0	0
Two Years before Current Fiscal Year	0	1,589
Three Years before Current Fiscal Year	1,550	3,627
Four Years before Current Fiscal Year	3,517	13,346
Prior	14,537	1,903
Revolving	0	0
Revolving Converted to Term During the Period	0	0
Total	19,604	20,465
Commercial loans | SBA non-real estate secured
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	10,761	11,045
Commercial loans | SBA non-real estate secured | 0% - 5.00%
Financing Receivable, Allowance for Credit Loss [Line Items]
Current Fiscal Year	663	474
Fiscal Year before Current Fiscal Year	467	564
Two Years before Current Fiscal Year	477	1,088
Three Years before Current Fiscal Year	87	370
Four Years before Current Fiscal Year	266	732
Prior	2,451	1,636
Revolving	0	0
Revolving Converted to Term During the Period	0	0
Total	4,411	4,864
Commercial loans | SBA non-real estate secured | >5.00% - 10.00%
Financing Receivable, Allowance for Credit Loss [Line Items]
Current Fiscal Year	0	0
Fiscal Year before Current Fiscal Year	0	0
Two Years before Current Fiscal Year	66	205
Three Years before Current Fiscal Year	1,775	410
Four Years before Current Fiscal Year	490	2,074
Prior	2,301	512
Revolving	0	0
Revolving Converted to Term During the Period	0	0
Total	4,632	3,201
Commercial loans | SBA non-real estate secured | Greater than 10%
Financing Receivable, Allowance for Credit Loss [Line Items]
Current Fiscal Year	0	0
Fiscal Year before Current Fiscal Year	0	0
Two Years before Current Fiscal Year	0	756
Three Years before Current Fiscal Year	140	339
Four Years before Current Fiscal Year	244	685
Prior	692	547
Revolving	642	653
Revolving Converted to Term During the Period	0	0
Total	1,718	2,980
Commercial loans | Total commercial loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Current Fiscal Year	103,115	591,794
Fiscal Year before Current Fiscal Year	579,752	104,142
Two Years before Current Fiscal Year	92,930	289,238
Three Years before Current Fiscal Year	265,527	169,961
Four Years before Current Fiscal Year	153,352	164,717
Prior	245,541	107,053
Revolving	1,198,751	1,075,204
Revolving Converted to Term During the Period	2,747	4,624
Total	$ 2,641,715	$ 2,506,733