Segment Reporting - Segment Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Segment Reporting Information [Line Items]
Net interest income	$ 3,179	$ 2,157	$ 2,097
Provision for credit losses	(123)	(220)	(107)
Noninterest income	2,738	1,840	1,221
Noninterest expense	(3,070)	(2,035)	(1,601)
Income before income tax expense	2,724	1,742	1,610
Total average loans, net of unearned income	54,547	37,266	29,916
Total average assets	166,011	85,792	63,212
Total average deposits	147,947	75,016	55,057
Global Commercial Bank
Segment Reporting Information [Line Items]
Noninterest income	708	606	638
Income before income tax expense	2,322	1,445
SVB Private Bank
Segment Reporting Information [Line Items]
Noninterest income	56	3	4
Income before income tax expense	24	13
SVB Capital
Segment Reporting Information [Line Items]
Noninterest income	487	226	122
Income before income tax expense	416	175
SVB Securities
Segment Reporting Information [Line Items]
Income before income tax expense	48	119
Operating segments | Global Commercial Bank
Segment Reporting Information [Line Items]
Net interest income	2,946	2,025	1,850
Provision for credit losses	(55)	(166)	(92)
Noninterest income	708	606	638
Noninterest expense	(1,277)	(1,020)	(875)
Income before income tax expense			1,521
Total average loans, net of unearned income	44,173	31,218	26,031
Total average assets	141,393	75,034	56,043
Total average deposits	138,336	72,127	53,054
Operating segments | SVB Private Bank
Segment Reporting Information [Line Items]
Net interest income	194	77	51
Provision for credit losses	(14)	(21)	(2)
Noninterest income	56	3	4
Noninterest expense	(212)	(46)	(40)
Income before income tax expense			13
Total average loans, net of unearned income	8,958	4,196	3,341
Total average assets	10,140	4,230	3,371
Total average deposits	8,645	2,172	1,524
Operating segments | SVB Capital
Segment Reporting Information [Line Items]
Net interest income	0	0	0
Provision for credit losses	0	0	0
Noninterest income	487	226	122
Noninterest expense	(71)	(51)	(31)
Income before income tax expense			91
Total average loans, net of unearned income	0	0	0
Total average assets	700	437	405
Total average deposits	0	0	0
Operating segments | SVB Securities
Segment Reporting Information [Line Items]
Net interest income	1	1	1
Provision for credit losses	0	0	0
Noninterest income	608	497	264
Noninterest expense	(561)	(379)	(253)
Income before income tax expense			12
Total average loans, net of unearned income	0	0	0
Total average assets	830	557	398
Total average deposits	0	0	0
Other Items
Segment Reporting Information [Line Items]
Net interest income	38	54	195
Provision for credit losses	(54)	(33)	(13)
Noninterest income	879	508	193
Noninterest expense	(949)	(539)	(402)
Income before income tax expense	(86)	(10)	(27)
Total average loans, net of unearned income	1,416	1,852	544
Total average assets	12,948	5,534	2,995
Total average deposits	$ 966	$ 717	$ 479