Noninterest Income - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									$ 1,056,842	$ 880,951	$ 511,656
Revenue not from contracts with customer									783,306	340,528	233,328
Noninterest income	$ 621,783	$ 547,583	$ 368,848	$ 301,934	$ 313,344	$ 294,009	$ 333,750	$ 280,376	1,840,148	1,221,479	744,984
Other Items
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									2,818	2,158	2,393
Revenue not from contracts with customer									506,131	191,123	118,827
Noninterest income									508,949	193,281	121,220
Global Commercial Bank
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									527,368	592,185	483,918
Revenue not from contracts with customer									78,365	45,737	36,384
Noninterest income									605,733	637,922	520,302
SVB Private Bank
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									3,470	2,563	2,329
Revenue not from contracts with customer									66	803	(48)
Noninterest income									3,536	3,366	2,281
SVB Capital
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									35,834	26,850	23,016
Revenue not from contracts with customer									190,120	95,544	78,165
Noninterest income									225,954	122,394	101,181
SVB Leerink
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									487,352	257,195
Revenue not from contracts with customer									8,624	7,321
Noninterest income									495,976	264,516
Client investment fees
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									132,200	182,068	130,360
Client investment fees | Other Items
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0	0	0
Client investment fees | Global Commercial Bank
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									129,378	180,152	128,834
Client investment fees | SVB Private Bank
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									2,822	1,916	1,526
Client investment fees | SVB Capital
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0	0	0
Client investment fees | SVB Leerink
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0	0
Spot contract commissions
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									157,852	145,915	127,459
Spot contract commissions | Other Items
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									583	475	323
Spot contract commissions | Global Commercial Bank
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									156,725	144,930	126,445
Spot contract commissions | SVB Private Bank
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									544	510	691
Spot contract commissions | SVB Capital
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0	0	0
Spot contract commissions | SVB Leerink
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0	0
Card interchange fees, gross
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									129,807	154,953	134,502
Card interchange fees, gross | Other Items
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									1,545	756	428
Card interchange fees, gross | Global Commercial Bank
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									128,239	154,197	134,074
Card interchange fees, gross | SVB Private Bank
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									23	0	0
Card interchange fees, gross | SVB Capital
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0	0	0
Card interchange fees, gross | SVB Leerink
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0	0
Merchant service fees
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									17,732	18,355	14,420
Merchant service fees | Other Items
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0	0	1
Merchant service fees | Global Commercial Bank
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									17,732	18,355	14,415
Merchant service fees | SVB Private Bank
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0	0	4
Merchant service fees | SVB Capital
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0	0	0
Merchant service fees | SVB Leerink
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0	0
Deposit service charges
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									90,336	89,200	76,097
Deposit service charges | Other Items
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									690	927	1,641
Deposit service charges | Global Commercial Bank
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									89,565	88,136	74,348
Deposit service charges | SVB Private Bank
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									81	137	108
Deposit service charges | SVB Capital
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0	0	0
Deposit service charges | SVB Leerink
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0	0
Investment banking revenue
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									413,985	195,177
Investment banking revenue | Other Items
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0	0
Investment banking revenue | Global Commercial Bank
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0	0
Investment banking revenue | SVB Private Bank
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0	0
Investment banking revenue | SVB Capital
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0	0
Investment banking revenue | SVB Leerink
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									413,985	195,177
Commissions
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									66,640	56,346
Commissions | Other Items
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0	0
Commissions | Global Commercial Bank
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0	0
Commissions | SVB Private Bank
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0	0
Commissions | SVB Capital
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0	0
Commissions | SVB Leerink
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									66,640	56,346
Fund management fees
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									38,960	32,522	23,016
Fund management fees | Other Items
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0	0	0
Fund management fees | Global Commercial Bank
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0	0	0
Fund management fees | SVB Private Bank
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0	0	0
Fund management fees | SVB Capital
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									32,233	26,850	23,016
Fund management fees | SVB Leerink
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									6,727	5,672
Correspondent bank rebates
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									5,729	6,415	5,802
Correspondent bank rebates | Other Items
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0	0	0
Correspondent bank rebates | Global Commercial Bank
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									5,729	6,415	5,802
Correspondent bank rebates | SVB Private Bank
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0	0	0
Correspondent bank rebates | SVB Capital
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0	0	$ 0
Correspondent bank rebates | SVB Leerink
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0	$ 0
Performance Fees [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									3,601
Performance Fees [Member] | Other Items
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0
Performance Fees [Member] | Global Commercial Bank
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0
Performance Fees [Member] | SVB Private Bank
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0
Performance Fees [Member] | SVB Capital
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									3,601
Performance Fees [Member] | SVB Leerink
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									$ 0