Stockholders' Equity and EPS - QTD Stockholders' Equity (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Stockholders Equity Note [Line Items]
Balance, beginning of period, net of tax	$ 16,276	$ 11,967	$ 16,609	$ 8,433
Common stock issued under employee benefit plans, net of restricted stock cancellations	(2)	2	(31)	(1)
Issuance of stock		1,245		2,363
Issuance of common stock for the acquisition of Boston Private		1,060		1,060
Net income	418	475	1,304	1,665
Capital calls and distributions, net	(6)	(19)	(19)	(70)
Other comprehensive income (loss), net of tax	(887)	(77)	(2,076)	(558)
Share-based compensation, net	51	38	146	93
Dividends on preferred stock	(40)	(22)	(123)	(40)
Balance, end of period, net of tax	15,810	14,669	15,810	14,669
Noncumulative Preferred Stock
Stockholders Equity Note [Line Items]
Issuance of stock				1,724
Preferred Stock
Stockholders Equity Note [Line Items]
Balance, beginning of period, net of tax	3,646	2,064	3,646	340
Balance, end of period, net of tax	$ 3,646	$ 2,064	$ 3,646	2,064
Preferred Stock | Noncumulative Preferred Stock
Stockholders Equity Note [Line Items]
Issuance of stock				$ 1,724
Common Stock
Stockholders Equity Note [Line Items]
Balance (in shares)	59,081,326	54,530,307	58,748,469	51,888,463
Balance, beginning of period, net of tax	$ 0	$ 0	$ 0	$ 0
Common stock issued under employee benefit plans, net of restricted stock cancellations (in shares)	22,798	32,195	355,655	374,039
Common stock issued under employee benefit plans, net of restricted stock cancellations			$ 0	$ 0
Issuance of stock (in shares)		2,227,000		4,527,000
Issuance of stock		$ 0		$ 0
Issuance of common stock for the acquisition of Boston Private (in shares)		1,887,981		1,887,981
Issuance of common stock for the acquisition of Boston Private		$ 0
Balance (in shares)	59,104,124	58,677,483	59,104,124	58,677,483
Balance, end of period, net of tax	$ 0	$ 0	$ 0	$ 0
Additional Paid-in Capital
Stockholders Equity Note [Line Items]
Balance, beginning of period, net of tax	5,223	2,755	5,157	1,585
Common stock issued under employee benefit plans, net of restricted stock cancellations	(2)	2	(31)	(1)
Issuance of stock		1,245		2,363
Issuance of common stock for the acquisition of Boston Private		1,060		1,060
Share-based compensation, net	51	38	146	93
Balance, end of period, net of tax	5,272	5,100	5,272	5,100
Retained Earnings
Stockholders Equity Note [Line Items]
Balance, beginning of period, net of tax	8,247	6,706	7,442	5,672
Net income	469	387	1,357	1,439
Dividends on preferred stock	(40)	(22)	(123)	(40)
Balance, end of period, net of tax	8,676	7,071	8,676	7,071
Accumulated Other Comprehensive Income (Loss)
Stockholders Equity Note [Line Items]
Balance, beginning of period, net of tax	(1,198)	142	(9)	623
Other comprehensive income (loss), net of tax	(887)	(77)	(2,076)	(558)
Balance, end of period, net of tax	(2,085)	65	(2,085)	65
Total SVBFG Stockholders’ Equity
Stockholders Equity Note [Line Items]
Balance, beginning of period, net of tax	15,918	11,667	16,236	8,220
Common stock issued under employee benefit plans, net of restricted stock cancellations	(2)	2	(31)	(1)
Issuance of stock		1,245		2,363
Issuance of common stock for the acquisition of Boston Private		1,060		1,060
Net income	469	387	1,357	1,439
Other comprehensive income (loss), net of tax	(887)	(77)	(2,076)	(558)
Share-based compensation, net	51	38	146	93
Dividends on preferred stock	(40)	(22)	(123)	(40)
Balance, end of period, net of tax	15,509	14,300	15,509	14,300
Total SVBFG Stockholders’ Equity | Noncumulative Preferred Stock
Stockholders Equity Note [Line Items]
Issuance of stock				1,724
Noncontrolling Interests
Stockholders Equity Note [Line Items]
Balance, beginning of period, net of tax	358	300	373	213
Net income	(51)	88	(53)	226
Capital calls and distributions, net	(6)	(19)	(19)	(70)
Balance, end of period, net of tax	$ 301	$ 369	$ 301	$ 369