Loans, Allowance for Loan Losses and Allowance for Unfunded Credit Commitments - Credit Quality Indicators, Broken out by Risk-Based Segments and Vintage Year (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	$ 9,153,860
2019	4,008,276
2018	1,861,154
2017	934,386
2016	530,328
Prior	598,525
Revolving Loans	28,040,704
Revolving Loans Converted to Term Loans	54,255
Loans, amortized cost	45,181,488	$ 33,164,636
Nonperforming
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amortized cost	104,244
Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amortized cost	43,825,846
Criticized
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amortized cost	1,251,398
Global fund banking
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	439,497
2019	48,305
2018	68,491
2017	22,878
2016	2,389
Prior	5,999
Revolving Loans	24,947,838
Revolving Loans Converted to Term Loans	7,801
Loans, amortized cost	25,543,198	17,696,794
Global fund banking \| Nonperforming
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	3
2019	8
2018	0
2017	0
2016	0
Prior	0
Revolving Loans	0
Revolving Loans Converted to Term Loans	0
Loans, amortized cost	11
Global fund banking \| Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	439,494
2019	48,297
2018	68,491
2017	22,878
2016	2,389
Prior	5,999
Revolving Loans	24,947,428
Revolving Loans Converted to Term Loans	2,378
Loans, amortized cost	25,537,354
Global fund banking \| Criticized
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving Loans	410
Revolving Loans Converted to Term Loans	5,423
Loans, amortized cost	5,833
Investor dependent
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	2,544,507
2019	1,253,486
2018	528,189
2017	115,532
2016	9,888
Prior	17,072
Revolving Loans	495,047
Revolving Loans Converted to Term Loans	8,097
Loans, amortized cost	4,971,818	4,335,195
Investor dependent \| Nonperforming
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amortized cost	51,053
Investor dependent \| Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amortized cost	4,454,347
Investor dependent \| Criticized
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amortized cost	466,418
Investor dependent \| Early stage
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	716,333
2019	452,038
2018	152,458
2017	42,808
2016	4,791
Prior	739
Revolving Loans	116,082
Revolving Loans Converted to Term Loans	617
Loans, amortized cost	1,485,866	1,624,221
Investor dependent \| Early stage \| Nonperforming
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	2,438
2019	9,354
2018	5,368
2017	441
2016	0
Prior	0
Revolving Loans	739
Revolving Loans Converted to Term Loans	0
Loans, amortized cost	18,340
Investor dependent \| Early stage \| Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	667,006
2019	370,189
2018	120,920
2017	32,163
2016	1,234
Prior	405
Revolving Loans	96,363
Revolving Loans Converted to Term Loans	617
Loans, amortized cost	1,288,897
Investor dependent \| Early stage \| Criticized
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	46,889
2019	72,495
2018	26,170
2017	10,204
2016	3,557
Prior	334
Revolving Loans	18,980
Revolving Loans Converted to Term Loans	0
Loans, amortized cost	178,629
Investor dependent \| Mid stage
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	883,729
2019	350,813
2018	171,829
2017	33,615
2016	5,086
Prior	6,699
Revolving Loans	110,604
Revolving Loans Converted to Term Loans	2,495
Loans, amortized cost	1,564,870	1,047,398
Investor dependent \| Mid stage \| Nonperforming
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	10
2019	614
2018	218
2017	2,539
2016	0
Prior	675
Revolving Loans	0
Revolving Loans Converted to Term Loans	0
Loans, amortized cost	4,056
Investor dependent \| Mid stage \| Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	840,431
2019	301,905
2018	145,588
2017	22,834
2016	5,086
Prior	1,026
Revolving Loans	101,423
Revolving Loans Converted to Term Loans	2,495
Loans, amortized cost	1,420,788
Investor dependent \| Mid stage \| Criticized
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	43,288
2019	48,294
2018	26,023
2017	8,242
2016	0
Prior	4,998
Revolving Loans	9,181
Revolving Loans Converted to Term Loans	0
Loans, amortized cost	140,026
Investor dependent \| Later stage
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	944,445
2019	450,635
2018	203,902
2017	39,109
2016	11
Prior	9,634
Revolving Loans	268,361
Revolving Loans Converted to Term Loans	4,985
Loans, amortized cost	1,921,082	1,663,576
Investor dependent \| Later stage \| Nonperforming
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	16,691
2019	1,797
2018	3,522
2017	0
2016	0
Prior	0
Revolving Loans	6,647
Revolving Loans Converted to Term Loans	0
Loans, amortized cost	28,657
Investor dependent \| Later stage \| Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	905,468
2019	393,584
2018	170,128
2017	37,967
2016	11
Prior	8,087
Revolving Loans	224,432
Revolving Loans Converted to Term Loans	4,985
Loans, amortized cost	1,744,662
Investor dependent \| Later stage \| Criticized
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	22,286
2019	55,254
2018	30,252
2017	1,142
2016	0
Prior	1,547
Revolving Loans	37,282
Revolving Loans Converted to Term Loans	0
Loans, amortized cost	147,763
Cash flow dependent
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	1,690,801
2019	1,114,850
2018	546,307
2017	333,316
2016	88,711
Prior	101
Revolving Loans	1,160,447
Revolving Loans Converted to Term Loans	0
Loans, amortized cost	4,934,533	4,424,238
Cash flow dependent \| Nonperforming
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amortized cost	46,000
Cash flow dependent \| Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amortized cost	4,473,343
Cash flow dependent \| Criticized
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amortized cost	415,190
Cash flow dependent \| Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	898,788
2019	581,096
2018	217,500
2017	137,712
2016	38,808
Prior	101
Revolving Loans	1,071,355
Revolving Loans Converted to Term Loans	0
Loans, amortized cost	2,945,360	2,238,741
Cash flow dependent \| Other \| Nonperforming
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	0
2019	0
2018	4,552
2017	0
2016	0
Prior	0
Revolving Loans	1,452
Revolving Loans Converted to Term Loans	0
Loans, amortized cost	6,004
Cash flow dependent \| Other \| Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	879,542
2019	513,242
2018	179,169
2017	133,235
2016	38,808
Prior	101
Revolving Loans	933,274
Revolving Loans Converted to Term Loans	0
Loans, amortized cost	2,677,371
Cash flow dependent \| Other \| Criticized
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	19,246
2019	67,854
2018	33,779
2017	4,477
2016	0
Prior	0
Revolving Loans	136,629
Revolving Loans Converted to Term Loans	0
Loans, amortized cost	261,985
Cash flow dependent \| Sponsor led buyout
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	792,013
2019	533,754
2018	328,807
2017	195,604
2016	49,903
Prior	0
Revolving Loans	89,092
Revolving Loans Converted to Term Loans	0
Loans, amortized cost	1,989,173	2,185,497
Cash flow dependent \| Sponsor led buyout \| Nonperforming
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	33
2019	11,869
2018	16,068
2017	7,177
2016	0
Prior	0
Revolving Loans	4,849
Revolving Loans Converted to Term Loans	0
Loans, amortized cost	39,996
Cash flow dependent \| Sponsor led buyout \| Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	791,480
2019	451,561
2018	273,719
2017	166,820
2016	36,900
Prior	0
Revolving Loans	75,492
Revolving Loans Converted to Term Loans	0
Loans, amortized cost	1,795,972
Cash flow dependent \| Sponsor led buyout \| Criticized
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	500
2019	70,324
2018	39,020
2017	21,607
2016	13,003
Prior	0
Revolving Loans	8,751
Revolving Loans Converted to Term Loans	0
Loans, amortized cost	153,205
Private Bank
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	1,881,664
2019	1,163,451
2018	402,034
2017	354,059
2016	299,971
Prior	415,313
Revolving Loans	383,904
Revolving Loans Converted to Term Loans	660
Loans, amortized cost	4,901,056	3,492,269
Private Bank \| Nonperforming
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	0
2019	563
2018	3,197
2017	0
2016	0
Prior	1,679
Revolving Loans	713
Revolving Loans Converted to Term Loans	0
Loans, amortized cost	6,152
Private Bank \| Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	1,878,184
2019	1,152,903
2018	394,351
2017	352,857
2016	294,870
Prior	405,909
Revolving Loans	382,442
Revolving Loans Converted to Term Loans	660
Loans, amortized cost	4,862,176
Private Bank \| Criticized
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	3,480
2019	9,985
2018	4,486
2017	1,202
2016	5,101
Prior	7,725
Revolving Loans	749
Revolving Loans Converted to Term Loans	0
Loans, amortized cost	32,728
Balance sheet dependent
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	893,500
2019	193,873
2018	198,703
2017	19,213
2016	0
Prior	0
Revolving Loans	884,229
Revolving Loans Converted to Term Loans	1,505
Loans, amortized cost	2,191,023	1,286,153
Balance sheet dependent \| Nonperforming
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving Loans	0
Revolving Loans Converted to Term Loans	0
Loans, amortized cost	0
Balance sheet dependent \| Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	837,613
2019	190,140
2018	198,532
2017	19,213
2016	0
Prior	0
Revolving Loans	857,642
Revolving Loans Converted to Term Loans	1,505
Loans, amortized cost	2,104,645
Balance sheet dependent \| Criticized
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	55,887
2019	3,733
2018	171
2017	0
2016	0
Prior	0
Revolving Loans	26,587
Revolving Loans Converted to Term Loans	0
Loans, amortized cost	86,378
Premium wine
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	144,358
2019	218,030
2018	106,520
2017	89,388
2016	129,369
Prior	159,607
Revolving Loans	169,179
Revolving Loans Converted to Term Loans	36,192
Loans, amortized cost	1,052,643	1,062,264
Premium wine \| Nonperforming
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	998
Prior	0
Revolving Loans	0
Revolving Loans Converted to Term Loans	0
Loans, amortized cost	998
Premium wine \| Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	126,476
2019	193,744
2018	70,783
2017	79,088
2016	114,812
Prior	153,841
Revolving Loans	135,461
Revolving Loans Converted to Term Loans	36,192
Loans, amortized cost	910,397
Premium wine \| Criticized
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	17,882
2019	24,286
2018	35,737
2017	10,300
2016	13,559
Prior	5,766
Revolving Loans	33,718
Revolving Loans Converted to Term Loans	0
Loans, amortized cost	141,248
Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	3
2019	16,281
2018	10,910
2017	0
2016	0
Prior	433
Revolving Loans	60
Revolving Loans Converted to Term Loans	0
Loans, amortized cost	27,687	867,723
Other \| Nonperforming
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	0
2019	30
2018	0
2017	0
2016	0
Prior	0
Revolving Loans	0
Revolving Loans Converted to Term Loans	0
Loans, amortized cost	30
Other \| Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	0
2019	16,251
2018	10,910
2017	0
2016	0
Prior	433
Revolving Loans	0
Revolving Loans Converted to Term Loans	0
Loans, amortized cost	27,594
Other \| Criticized
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	3
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving Loans	60
Revolving Loans Converted to Term Loans	0
Loans, amortized cost	63
SBA loans

Loans, Allowance for Loan Losses and Allowance for Unfunded Credit Commitments - Credit Quality Indicators, Broken out by Risk-Based Segments and Vintage Year (Details) - USD ($)
$ in Thousands