Parent Company Only Condensed Financial Information Condensed Statements of Cash Flows (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015		Dec. 31, 2014
Adjustments to reconcile net income to net cash used for operating activities:
Gains on derivative instruments, net	$ (48,581)	$ (83,805)		$ (96,845)
Gains on investment securities, net	(51,740)	(89,445)	[1],[2]	(267,023)
Amortization of share-based compensation	35,494	32,239		29,545
Impairment loss on SVBIF Sale Transaction	0	0		13,934
Other, net	41,684	64,044		19,788
Net cash used for operating activities	437,977	339,197		255,268
Cash flows from investing activities:
Net (increase) decrease in loans	(3,169,493)	(2,335,153)		(3,480,531)
Net cash used for investing activities	1,015,344	(6,495,736)		(12,233,682)
Cash flows from financing activities:
Proceeds from issuance of common stock, ESPP, and ESOP	26,147	22,410		22,146
Tax benefit from stock exercises	(3,640)	16,602		9,602
Net proceeds from public equity offering	0	0		434,866
Net cash provided by financing activities	(410,828)	5,848,782		12,250,649
Net increase (decrease) in cash and cash equivalents	1,042,493	(307,757)		272,235
Cash and cash equivalents at beginning of period	1,503,257	1,811,014	[3]	1,538,779
Cash and cash equivalents at end of period	2,545,750	1,503,257		1,811,014	[3]
Parent Company
Cash flows from operating activities:
Net income attributable to SVBFG	382,685	343,904		263,870
Adjustments to reconcile net income to net cash used for operating activities:
Gains on derivative instruments, net	(35,608)	(55,477)		(66,604)
Gains on investment securities, net	(20,644)	(39,447)		(8,750)
Net income of subsidiaries	(31,107)	(10,221)		8,529
Cash dividends from bank subsidiary	40,000	0		0
Amortization of share-based compensation	35,494	32,239		29,545
Decrease (increase) in other assets	35,699	(30,638)		46,512
Increase (decrease) in other liabilities	15,293	28,985		25,697
Impairment loss on SVBIF Sale Transaction	0	0		9,564
Other, net	708	470		513
Net cash used for operating activities	62,049	(53,647)		27,948
Cash flows from investing activities:
Net decrease in investment securities from purchases, sales and maturities	54,737	31,380		15,469
Net (increase) decrease in loans	(3,478)	6,825		(11,893)
Net cash used for investing activities	38,445	(269,019)		(398,474)
Cash flows from financing activities:
Proceeds from issuance of common stock, ESPP, and ESOP	26,147	22,410		22,146
Tax benefit from stock exercises	(3,640)	16,602		9,602
Net proceeds from public equity offering	0	0		434,866
Proceeds from Issuance of Long-term Debt	0	346,431		0
Net cash provided by financing activities	22,507	385,443		466,614
Net increase (decrease) in cash and cash equivalents	123,001	62,777		96,088
Cash and cash equivalents at beginning of period	377,013	314,236		218,148
Cash and cash equivalents at end of period	500,014	377,013		314,236
Parent Company | Bank Subsidiaries
Adjustments to reconcile net income to net cash used for operating activities:
Net income of subsidiaries	(379,629)	(306,864)		(249,350)
Cash flows from investing activities:
Investment in subsidiaries	(14,738)	(378,286)		(432,804)
Parent Company | Nonbank Subsidiaries
Adjustments to reconcile net income to net cash used for operating activities:
Net income of subsidiaries	(11,949)	(26,819)		(23,049)
Cash flows from investing activities:
Investment in subsidiaries	$ 1,924	$ 71,062		$ 30,754

[1] During the second quarter of 2015 we adopted new accounting guidance related to our consolidated variable interest entities (ASU 2015-02). Amounts prior to January 1, 2015 have not been revised for the adoption of this guidance. See Note 2— "Summary of Significant Accounting Policies” of the “Notes to the Consolidated Financial Statements” under Part II, Item 8 of this report for additional details.

[2] During the second quarter of 2015 we adopted new accounting guidance related to our consolidated variable interest entities (ASU 2015-02). Amounts prior to January 1, 2015 have not been revised for the adoption of this guidance. See Note 2— "Summary of Significant Accounting Policies” of the “Notes to the Consolidated Financial Statements” under Part II, Item 8 of this report for additional details.

[3] Cash and cash equivalents at December 31, 2014 included $15.0 million recognized in assets held-for-sale in conjunction with the SVBIF sale transaction. On April 13, 2015 we received net proceeds of $39.3 million consisting of the sales price of $48.6 million less $9.3 million of cash and cash equivalents held by SVBIF that were sold.