Noninterest Income - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 217,257	$ 111,362
Revenues outside the scope of ASC 606	63,119	44,156
Noninterest income	280,376	155,518
Global Commercial Bank
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	117,873	92,013
Revenues outside the scope of ASC 606	8,444	6,779
Noninterest income	126,317	98,792
SVB Private Bank
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	537	509
Revenues outside the scope of ASC 606	(27)	(2)
Noninterest income	510	507
SVB Capital
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	6,659	5,736
Revenues outside the scope of ASC 606	18,186	23,174
Noninterest income	24,845	28,910
SVB Leerink Segment
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	65,285
Revenues outside the scope of ASC 606	2,832
Noninterest income	68,117
Other Income
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	26,903	13,104
Revenues outside the scope of ASC 606	33,684	14,205
Noninterest income	60,587	27,309
Spot contract commissions
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	35,029	31,202
Spot contract commissions | Global Commercial Bank
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	34,806	30,972
Spot contract commissions | SVB Private Bank
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	122	179
Spot contract commissions | SVB Capital
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Spot contract commissions | SVB Leerink Segment
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0
Spot contract commissions | Other Income
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	101	51
Card interchange fees, gross
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	38,862	29,548
Card interchange fees, gross | Global Commercial Bank
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	38,715	29,449
Card interchange fees, gross | SVB Private Bank
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Card interchange fees, gross | SVB Capital
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Card interchange fees, gross | SVB Leerink Segment
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0
Card interchange fees, gross | Other Income
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	147	99
Merchant service fees
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	4,534	2,906
Merchant service fees | Global Commercial Bank
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	4,534	2,906
Merchant service fees | SVB Private Bank
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Merchant service fees | SVB Capital
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Merchant service fees | SVB Leerink Segment
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0
Merchant service fees | Other Income
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	20,939	17,699
Deposit service charges | Global Commercial Bank
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	20,793	17,040
Deposit service charges | SVB Private Bank
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	35	28
Deposit service charges | SVB Capital
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Deposit service charges | SVB Leerink Segment
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0
Deposit service charges | Other Income
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	111	631
Client investment fees
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	44,482	22,875
Client investment fees | Global Commercial Bank
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	17,558	10,250
Client investment fees | SVB Private Bank
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	380	302
Client investment fees | SVB Capital
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Client investment fees | SVB Leerink Segment
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0
Client investment fees | Other Income
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	26,544	12,323
Investment banking revenue
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	49,795
Investment banking revenue | Global Commercial Bank
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0
Investment banking revenue | SVB Private Bank
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0
Investment banking revenue | SVB Capital
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0
Investment banking revenue | SVB Leerink Segment
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	49,795
Investment banking revenue | Other Income
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0
Commissions
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	14,108
Commissions | Global Commercial Bank
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0
Commissions | SVB Private Bank
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0
Commissions | SVB Capital
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0
Commissions | SVB Leerink Segment
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	14,108
Commissions | Other Income
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0
Fund management fees
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	8,041	5,736
Fund management fees | Global Commercial Bank
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Fund management fees | SVB Private Bank
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Fund management fees | SVB Capital
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	6,659	5,736
Fund management fees | SVB Leerink Segment
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,382
Fund management fees | Other Income
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Correspondent bank rebates
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,467	1,396
Correspondent bank rebates | Global Commercial Bank
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,467	1,396
Correspondent bank rebates | SVB Private Bank
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Correspondent bank rebates | SVB Capital
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Correspondent bank rebates | SVB Leerink Segment
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0
Correspondent bank rebates | Other Income
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 0	$ 0