SVB Financial (SIVBQ) 10-Q 11 May 15 2015 Q1 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	3 Months Ended
	Mar. 31, 2015	Apr. 30, 2015
Document and Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	FALSE
Document Period End Date	31-Mar-15
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q1
Trading Symbol	SIVB
Entity Registrant Name	SVB FINANCIAL GROUP
Entity Central Index Key	719739
Current Fiscal Year End Date	-19
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		51,240,105

Interim_Consolidated_Balance_S

Interim Consolidated Balance Sheets (USD $)	Mar. 31, 2015		Dec. 31, 2014
In Thousands, unless otherwise specified
Assets
Cash and cash equivalents	$1,308,003		$1,796,062
Available-for-sale securities, at fair value (cost of $13,619,702 and $13,497,945, respectively)	13,746,923		13,540,655
Held-to-maturity securities, at cost (fair value of $7,869,653 and $7,415,656, respectively)	7,816,797		7,421,042
Non-marketable and other securities	1,706,873		1,728,140	[1]
Total investment securities	23,270,593		22,689,837
Loans, net of unearned income	14,439,574	[2]	14,384,276	[2]
Allowance for loan losses	-167,875		-165,359
Net loans	14,271,699		14,218,917
Premises and equipment, net of accumulated depreciation and amortization	82,724		79,845
Accrued interest receivable and other assets	762,971		555,289	[1]
Total assets	39,695,990		39,339,950
Liabilities:
Noninterest-bearing demand deposits	25,716,586		24,583,682
Interest-bearing deposits	8,134,989		9,759,817
Total deposits	33,851,575		34,343,499
Short-term borrowings	77,766		7,781
Other liabilities	686,501		483,493
Long-term debt	802,917		453,443
Total liabilities	35,418,759		35,288,216
Commitments and contingencies (Note 12 and Note 15)
SVBFG stockholders’ equity:
Preferred stock, $0.001 par value, 20,000,000 shares authorized; no shares issued and outstanding	0		0
Common stock, $0.001 par value, 150,000,000 shares authorized; 51,095,341 shares and 50,924,925 shares outstanding, respectively	51		51
Additional paid-in capital	1,140,435		1,120,350
Retained earnings	1,738,483		1,649,967	[1]
Accumulated other comprehensive income	92,668		42,704
Total SVBFG stockholders’ equity	2,971,637		2,813,072
Noncontrolling interests	1,305,594		1,238,662
Total equity	4,277,231		4,051,734
Total liabilities and total equity	$39,695,990		$39,339,950
[1]	Prior period amounts have been revised to reflect the retrospective application of new accounting guidance adopted in the first quarter of 2015 related to our investments in qualified affordable housing projects (ASU 2014-01). See Note 1 - "Basis of Presentation" of the "Notes to Interim Consolidated Financial Statements" under Part I, Item 1 in this report.
[2]	Included within our total loan portfolio are credit card loans of $154 million and $131 million at March 31, 2015 and December 31, 2014, respectively.

Interim_Consolidated_Balance_S1

Interim Consolidated Balance Sheets (Parenthetical) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, except Share data, unless otherwise specified
Statement of Financial Position [Abstract]
Available-for-sale securities, cost	$13,619,702	$13,497,945
Held-to-maturity securities	$7,869,653	$7,415,656
Preferred stock, par value	$0.00	$0.00
Preferred stock, shares authorized	20,000,000	20,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$0.00	$0.00
Common stock, shares authorized	150,000,000	150,000,000
Common stock, shares outstanding	51,095,341	50,924,925

Interim_Consolidated_Statement

Interim Consolidated Statements of Income (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2015		Mar. 31, 2014
Interest income:
Loans	$165,458		$148,172
Investment securities:
Taxable	81,274		54,420
Non-taxable	772		796
Federal funds sold, securities purchased under agreements to resell and other short-term investment securities	1,285		1,636
Total interest income	248,789		205,024
Interest expense:
Deposits	1,943		2,904
Borrowings	7,956		5,792
Total interest expense	9,899		8,696
Net interest income	238,890		196,328
Provision for loan losses	6,452		494
Net interest income after provision for loan losses	232,438		195,834
Noninterest income:
Gains on investment securities, net	83,159		223,912
Gains on derivative instruments, net	39,729		24,167
Foreign exchange fees	17,678		17,196
Credit card fees	12,090		10,282
Deposit service charges	10,736		9,607
Lending related fees	8,022		6,303
Letters of credit and standby letters of credit fees	5,202		4,140
Client investment fees	4,482		3,418
Other	-9,080		11,200
Total noninterest income	172,018		310,225
Noninterest expense:
Compensation and benefits	115,770		102,507
Professional services	24,185		21,189
Premises and equipment	12,657		11,582
Business development and travel	11,112		10,194
Net occupancy	7,313		7,320
FDIC and state assessments	5,789		4,128
Correspondent bank fees	3,421		3,203
Provision for unfunded credit commitments	2,263		1,123
Other	13,598		9,162	[1]
Total noninterest expense	196,108	[2]	170,408	[1],[2]
Income before income tax expense	208,348	[3]	335,651	[1],[3]
Income tax expense	63,066		61,296	[1]
Net income before noncontrolling interests	145,282	[4]	274,355	[1],[4]
Net income attributable to noncontrolling interests	-56,766		-183,405
Net income available to common stockholders	$88,516		$90,950	[1],[5]
Earnings per common share—basic (dollars per share)	$1.74		$1.98	[1],[5]
Earnings per common share—diluted (dollars per share)	$1.71		$1.95
[1]	Prior period amounts have been revised to reflect the retrospective application of new accounting guidance adopted in the first quarter of 2015 related to our investments in qualified affordable housing projects (ASU 2014-01). See Note 1 - "Basis of Presentation" of the "Notes to Interim Consolidated Financial Statements" under Part I, Item 1 in this report.
[2]	The Global Commercial Bank segment includes direct depreciation and amortization of $5.1 million and $4.9 million for the three months ended March 31, 2015 and 2014, respectively
[3]	The internal reporting model used by management to assess segment performance does not calculate income tax expense by segment. Our effective tax rate is a reasonable approximation of the segment rates.
[4]	Cash flows for the quarters ended March 31, 2015 and March 31, 2014 were revised to reflect the retrospective application of our adoption of ASU 2014-01.
[5]	Results for the quarter ended March 31, 2014 were restated to reflect the retrospective application of adopting new accounting guidance in 2015 related to our investments in qualified affordable housing projects (ASU 2014-01). See Note 1 of the Notes to Consolidated Financial Statements for additional information.

Interim_Consolidated_Statement1

Interim Consolidated Statements of Comprehensive Income (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015		Mar. 31, 2014
Statement of Comprehensive Income [Abstract]
Net income before noncontrolling interests	$145,282	[1]	$274,355	[1],[2]
Change in cumulative translation gains:
Foreign currency translation gains	2,129		1,464
Related tax expense	-820		-578
Change in unrealized gains on available-for-sale securities:
Unrealized holding gains	87,107		29,329
Related tax expense	-35,215		-11,805
Reclassification adjustment for gains included in net income	-2,596		-60
Related tax expense	1,048		24
Amortization of unrealized gains on securities transferred from available-for-sale to held-to-maturity	-2,828		0
Related tax benefit	1,139		0
Other comprehensive income, net of tax	49,964		18,374
Comprehensive income	195,246		292,729
Comprehensive income attributable to noncontrolling interests	-56,766		-183,405
Comprehensive income attributable to SVBFG	$138,480		$109,324
[1]	Cash flows for the quarters ended March 31, 2015 and March 31, 2014 were revised to reflect the retrospective application of our adoption of ASU 2014-01.
[2]	Prior period amounts have been revised to reflect the retrospective application of new accounting guidance adopted in the first quarter of 2015 related to our investments in qualified affordable housing projects (ASU 2014-01). See Note 1 - "Basis of Presentation" of the "Notes to Interim Consolidated Financial Statements" under Part I, Item 1 in this report.

Interim_Consolidated_Statement2

Interim Consolidated Statements of Stockholders' Equity (USD $)		Total		Common Stock	Additional Paid-in Capital	Retained Earnings		Accumulated Other Comprehensive Income (Loss)	Total SVBFG Stockholders’ Equity		Noncontrolling Interests
In Thousands, except Share data, unless otherwise specified
Balance at Dec. 31, 2012
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effective of adopting ASU 2014-01 (Accounting Standards Update 2014-01)	[1]	($4,635)				($4,635)			($4,635)
Balance at Dec. 31, 2013 (Previously Reported)		3,079,328		46	624,256	1,390,732		-48,764	1,966,270		1,113,058
Balance (in shares) at Dec. 31, 2013 (Previously Reported)				45,800,418
Balance at Dec. 31, 2013		3,074,693		46	624,256	1,386,097		-48,764	1,961,635		1,113,058
Balance (in shares) at Dec. 31, 2013				45,800,418
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock issued under employee benefit plans, net of restricted stock cancellations (in shares)				103,341
Common stock issued under employee benefit plans, net of restricted stock cancellations		4,254		0	4,254				4,254
Common stock issued under ESOP (in shares)				30,762
Common stock issued under ESOP		3,890			3,890				3,890
Income tax benefit from stock options exercised, vesting of restricted stock and other		1,996			1,996				1,996
Net income		274,355	[1],[2]			90,950	[1]		90,950	[1]	183,405
Capital calls and distributions, net		-23,482									-23,482
Net change in unrealized gains and losses on available-for-sale securities, net of tax		17,488						17,488	17,488
Foreign currency translation adjustments, net of tax		886						886	886
Share-based compensation expense		7,892			7,892				7,892
Other, net		23			23	0			23
Balance at Mar. 31, 2014		3,361,995	[1]	46	642,311	1,477,047	[1]	-30,390	2,089,014	[1]	1,272,981
Balance (in shares) at Mar. 31, 2014				45,934,521
Balance at Dec. 31, 2014		4,051,734		51	1,120,350	1,649,967		42,704	2,813,072	[1]	1,238,662
Balance (in shares) at Dec. 31, 2014				50,924,925
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock issued under employee benefit plans, net of restricted stock cancellations (in shares)				142,991
Common stock issued under employee benefit plans, net of restricted stock cancellations		6,595			6,595				6,595
Common stock issued under ESOP (in shares)				27,425
Common stock issued under ESOP		3,512			3,512				3,512
Income tax benefit from stock options exercised, vesting of restricted stock and other		2,514			2,514				2,514
Net income		145,282	[2]			88,516			88,516		56,766
Capital calls and distributions, net		10,166									10,166
Net change in unrealized gains and losses on available-for-sale securities, net of tax		50,344						50,344	50,344
Amortization of unrealized gains on securities transferred from available-for-sale to held-to-maturity, net of tax		-1,689						-1,689	-1,689
Foreign currency translation adjustments, net of tax		1,309						1,309	1,309
Share-based compensation expense		7,464			7,464				7,464
Balance at Mar. 31, 2015		$4,277,231		$51	$1,140,435	$1,738,483		$92,668	$2,971,637		$1,305,594
Balance (in shares) at Mar. 31, 2015				51,095,341
[1]	Prior period amounts have been revised to reflect the retrospective application of new accounting guidance adopted in the first quarter of 2015 related to our investments in qualified affordable housing projects (ASU 2014-01). See Note 1 - "Basis of Presentation" of the "Notes to Interim Consolidated Financial Statements" under Part I, Item 1 in this report.
[2]	Cash flows for the quarters ended March 31, 2015 and March 31, 2014 were revised to reflect the retrospective application of our adoption of ASU 2014-01.

Interim_Consolidated_Statement3

Interim Consolidated Statements of Cash Flows (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015		Mar. 31, 2014
Cash flows from operating activities:
Net income before noncontrolling interests	$145,282	[1]	$274,355	[1],[2]
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan losses	6,452		494
Provision for unfunded credit commitments	2,263		1,123
Changes in fair values of derivatives, net	-20,404		13,356
Gains on investment securities, net	-83,159		-223,912
Depreciation and amortization	9,892		9,765
Amortization of premiums and discounts on investment securities, net	6,418		7,541
Amortization of share-based compensation	7,771		7,078
Amortization of deferred loan fees	-21,169		-20,502
Gain (Loss) on Disposition of Other Assets	-887		0
Deferred income tax benefit	1,311		15,828
Changes in other assets and liabilities:
Accrued interest receivable and payable, net	772		-6,604
Accounts receivable and payable, net	-4,015		-7,885
Income tax payable and receivable, net	9,283	[1]	25,159	[1]
Accrued compensation	-74,614		-74,687
Foreign exchange spot contracts, net	33,934		22,634
Other, net	28,486		6,247
Net cash provided by operating activities	47,616		49,990
Cash flows from investing activities:
Purchases of available-for-sale securities	-552,573		-1,531,045
Proceeds from sales of available-for-sale securities	5,612		2,097
Proceeds from maturities and pay downs of available-for-sale securities	424,713		694,243
Purchases of held-to-maturity securities	-739,291		0
Proceeds from maturities and pay downs of held-to-maturity securities	336,511		0
Purchases of non-marketable and other securities (cost and equity method accounting)	-7,304		-9,824
Proceeds from sales and distributions of non-marketable and other securities (cost and equity method accounting)	14,123		19,053
Purchases of non-marketable and other securities (fair value accounting)	-60,039		-45,125
Proceeds from sales and distributions of non-marketable and other securities (fair value accounting)	154,031		92,558
Net (increase) decrease in loans	-53,886		66,086
Proceeds from recoveries of charged-off loans	1,551		1,312
Purchases of premises and equipment	-12,038		-5,974
Net cash used for investing activities	-488,590		-716,619
Cash flows from financing activities:
Net (decrease) increase in deposits	-491,924		3,003,926
Increase (decrease) in short-term borrowings	69,985		-270
Net capital contributions from (distributions to) noncontrolling interests	10,166		-23,482
Tax benefit from stock exercises	2,514		1,996
Proceeds from issuance of common stock, ESPP, and ESOP	10,107		8,144
Proceeds from issuance of 3.50% Senior Notes	346,431		0
Net cash (used for) provided by financing activities	-52,721		2,990,314
Net (decrease) increase in cash and cash equivalents	-493,695		2,323,685
Cash and cash equivalents at beginning of period	1,796,062		1,538,779
Cash and cash equivalents at end of period	1,308,003		3,862,464
Cash and cash equivalents, including discontinued operations, at beginning of period	1,811,014	[3]
Cash and cash equivalents, including discontinued operations, at end of period	1,317,319	[3]
Cash paid during the period for:
Interest	11,859		12,688
Income taxes	46,599		15,486
Noncash items during the period:
Changes in unrealized gains and losses on available-for-sale securities, net of tax	$50,344		$17,488
[1]	Cash flows for the quarters ended March 31, 2015 and March 31, 2014 were revised to reflect the retrospective application of our adoption of ASU 2014-01.
[2]	Prior period amounts have been revised to reflect the retrospective application of new accounting guidance adopted in the first quarter of 2015 related to our investments in qualified affordable housing projects (ASU 2014-01). See Note 1 - "Basis of Presentation" of the "Notes to Interim Consolidated Financial Statements" under Part I, Item 1 in this report.
[3]	Cash and cash equivalents at March 31, 2015 and December 31, 2014 included $9.3 million and $15.0 million, respectively, recognized in assets held-for-sale in conjunction with the pending sale of SVBIF (refer to Note 7—”Disposal - Assets Held-for-Sale” of the “Notes to Interim Consolidated Financial Statements” under Part I, Item 1 of this report.

Interim_Consolidated_Statement4

Interim Consolidated Statements of Cash Flows (Parenthetical) (USD $)	Mar. 31, 2015		Dec. 31, 2014
In Thousands, unless otherwise specified
Cash and cash equivalents, including discontinued operations	$1,317,319	[1]	$1,811,014	[1]
Other assets
Cash and cash equivalents, including discontinued operations	$9,300		$15,000
[1]	Cash and cash equivalents at March 31, 2015 and December 31, 2014 included $9.3 million and $15.0 million, respectively, recognized in assets held-for-sale in conjunction with the pending sale of SVBIF (refer to Note 7—”Disposal - Assets Held-for-Sale” of the “Notes to Interim Consolidated Financial Statements” under Part I, Item 1 of this report.

Basis_of_Presentation

Basis of Presentation	3 Months Ended
	Mar. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation
	SVB Financial Group is a diversified financial services company, as well as a bank holding company and financial holding company. SVB Financial was incorporated in the state of Delaware in March 1999. Through our various subsidiaries and divisions, we offer a variety of banking and financial products and services to support our clients of all sizes and stages throughout their life cycles. In these notes to our consolidated financial statements, when we refer to “SVB Financial Group,” “SVBFG”, the “Company,” “we,” “our,” “us” or use similar words, we mean SVB Financial Group and all of its subsidiaries collectively, including Silicon Valley Bank (the “Bank”), unless the context requires otherwise. When we refer to “SVB Financial” or the “Parent” we are referring only to the parent company, SVB Financial Group, unless the context requires otherwise.
	The accompanying unaudited interim consolidated financial statements reflect all adjustments of a normal and recurring nature that are, in the opinion of management, necessary to fairly present our financial position, results of operations and cash flows in accordance with GAAP. Such unaudited interim consolidated financial statements have been prepared in accordance with the instructions to Form 10-Q pursuant to the rules and regulations of the SEC. Certain information and footnote disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations. The results of operations for the three months ended March 31, 2015 are not necessarily indicative of results to be expected for any future periods. These unaudited interim consolidated financial statements should be read in conjunction with our Annual Report on Form 10-K for the year ended December 31, 2014 (“2014 Form 10-K”).
	The preparation of unaudited interim consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Estimates may change as new information is obtained. Significant items that are subject to such estimates include measurements of fair value, the valuation of non-marketable securities, the valuation of equity warrant assets, the adequacy of the allowance for loan losses and reserve for unfunded credit commitments, and the recognition and measurement of income tax assets and liabilities.
	Principles of Consolidation and Presentation
	Our consolidated financial statements include the accounts of SVB Financial Group and entities in which we have a controlling financial interest. We determine whether we have a controlling financial interest in an entity by evaluating whether the entity is a voting interest entity or a VIE and whether the applicable accounting guidance requires consolidation. All significant intercompany accounts and transactions have been eliminated.
	Voting interest entities are entities that have sufficient equity and provide the equity investors voting rights that enable them to make significant decisions relating to the entity’s operations. For these types of entities, the Company’s determination of whether it has a controlling interest is based on ownership of the majority of the entities’ voting equity interest or through control of management of the entities.
	VIEs are entities that, by design, either (1) lack sufficient equity to permit the entity to finance its activities without additional subordinated financial support from other parties, or (2) have equity investors that do not have the ability to make significant decisions relating to the entity’s operations through voting rights, or do not have the obligation to absorb the expected losses, or do not have the right to receive the residual returns of the entity. We determine whether we have a controlling financial interest in a VIE by considering whether our involvement with the VIE is significant and whether we are the primary beneficiary based on the following:
	1	We have the power to direct the activities of the VIE that most significantly impact the entity’s economic performance;
	2	The aggregate indirect and direct variable interests held by the Company have the obligation to absorb losses or the right to receive benefits from the entity that could be significant to the VIE; and,
	3	Qualitative and quantitative factors regarding the nature, size, and form of our involvement with the VIE.
	Voting interest entities in which we have a controlling financial interest or VIEs in which we are the primary beneficiary are consolidated into our financial statements.
	We have not provided financial or other support during the periods presented to any VIE that we were not previously contractually required to provide. We are variable interest holders in certain partnerships for which we are not the primary beneficiary. We perform on-going reassessments on the status of the entities and whether facts or circumstances have changed in relation to previously evaluated voting interest entities and our involvement in VIEs which could cause our consolidation conclusion to change.
	Adoption of New Accounting Standards
	In January 2014, the FASB issued a new accounting standard (ASU 2014-01, Investments - Equity Method and Joint Ventures (Topic 323), Accounting for Investments in Qualified Affordable Housing Projects), which is effective for us for interim and annual reporting periods beginning after December 15, 2014. The standard is required to be applied retrospectively, with an adjustment to retained earnings in the earliest period presented. The ASU will be applicable to our portfolio of low income housing tax credit ("LIHTC") partnership interests. We adopted this guidance in the first quarter of 2015.
	For prior periods, pursuant to ASU 2014-01, (i) amortization expense related to our low income housing tax credits was reclassified from Other noninterest expense to Income tax expense, (ii) additional amortization, net of the associated tax benefits, was recognized in Income tax expense as a result of our adoption of the proportional amortization method and (iii) net deferred tax assets, related to our low income housing tax investments, were written-off. The cumulative effect to retained earnings as of January 1, 2015 of adopting this guidance was a reduction of $4.7 million, inclusive of a $4.6 million reduction to retained earnings as of January 1, 2014. Our previously reported net income for the first quarter of 2014 decreased $0.4 million. This reduction had no impact on first quarter 2014 diluted earnings per share.
	Recent Accounting Pronouncements
	In May 2014, the FASB issued a new accounting standard (ASU 2014-09, Revenue from Contracts with Customers (Topic 606)), which provides revenue recognition guidance that is intended to create greater consistency with respect to how and when revenue from contracts with customers is shown in the income statement. The guidance requires that revenue from contracts with customers be recognized upon delivery of a good or service based on the amount of consideration expected to be received, and requires additional disclosures about revenue. On April 29, 2015 the FASB issued an exposure draft to defer the effective date of Update 2014-09. If the FASB issues the proposed update, the guidance will be effective on a retrospective basis beginning on January 1, 2018. We do not expect the adoption of this guidance to have a material impact on our financial position, results of operations or stockholders' equity.
	In August 2014, the FASB issued a new accounting standard (ASU 2014-15, Going Concern (Topic 205-40)), which requires management to evaluate for each annual and interim reporting period whether there is substantial doubt about an entity's ability to continue as a going concern. The guidance will be effective for annual and quarterly periods beginning on or after December 15, 2016, with early adoption permitted. We are currently developing processes and controls to adopt this guidance by the adoption deadline and do not expect the adoption of this guidance to have a material impact on our financial position, results of operations or stockholders' equity.
	In February 2015, the FASB issued a new accounting standard (ASU 2015-02, Consolidation (Topic 810)), which amends the consolidation requirement for certain legal entities. The guidance will be effective for annual and quarterly periods beginning on January 1, 2016, with early adoption permitted. The standard may be applied using a modified retrospective approach by recording a cumulative-effect adjustment to equity as of the beginning of the fiscal year of adoption. We are currently assessing the impact this amendment is expected to have upon adoption.
	In April 2015, the FASB issued a new accounting standard (ASU 2015-03, Interest- Imputation of Interest (Subtopic 835-30), which simplifies the presentation of debt issuance costs. The guidance will be effective for annual and quarterly periods beginning on January 1, 2016, with early adoption permitted. We do not expect the adoption of this guidance to have a material impact on our financial position.
	Reclassifications
	Certain prior period amounts have been reclassified to conform to current period presentations.

Stockholders_Equity_and_EPS

Stockholders' Equity and EPS	3 Months Ended
	Mar. 31, 2015
Equity and Earnings Per Share [Abstract]
Stockholders' Equity and EPS	Stockholders’ Equity and EPS
	Accumulated Other Comprehensive Income
	The following table summarizes the items reclassified out of accumulated other comprehensive income into the Consolidated Statements of Income (unaudited) for the three months ended March 31, 2015 and 2014:
					Three months ended March 31,
	(Dollars in thousands)		Income Statement Location		2015				2014
	Reclassification adjustment for gains included in net income		Gains on investment securities, net		$	(2,596	)		$	(60	)
	Related tax expense		Income tax expense		1,048				24
	Total reclassification adjustment for gains included in net income, net of tax				$	(1,548	)		$	(36	)
	EPS
	Basic EPS is the amount of earnings available to each share of common stock outstanding during the reporting period. Diluted EPS is the amount of earnings available to each share of common stock outstanding during the reporting period adjusted to include the effect of potentially dilutive common shares. Potentially dilutive common shares include incremental shares issued for stock options and restricted stock units outstanding under our equity incentive plans and our ESPP. Potentially dilutive common shares are excluded from the computation of dilutive EPS in periods in which the effect would be antidilutive. The following is a reconciliation of basic EPS to diluted EPS for the three months ended March 31, 2015 and 2014:
			Three months ended March 31,
	(Dollars and shares in thousands, except per share amounts)		2015				2014
	Numerator:
	Net income available to common stockholders (1)		$	88,516			$	90,950
	Denominator:
	Weighted average common shares outstanding-basic		51,009				45,866
	Weighted average effect of dilutive securities:
	Stock options and ESPP		445				566
	Restricted stock units		265				293
	Denominator for diluted calculation		51,719				46,725
	Earnings per common share:
	Basic (1)		$	1.74			$	1.98
	Diluted		$	1.71			$	1.95
	-1	Results for the quarter ended March 31, 2014 were restated to reflect the retrospective application of adopting new accounting guidance in 2015 related to our investments in qualified affordable housing projects (ASU 2014-01). See Note 1 of the Notes to Consolidated Financial Statements for additional information.
	The following table summarizes the weighted-average common shares excluded from the diluted EPS calculation as they were deemed to be antidilutive for the three months ended March 31, 2015 and 2014:
			Three months ended March 31,
	(Shares in thousands)		2015			2014
	Stock options		241			6
	Restricted stock units		2			1
	Total		243			7

ShareBased_Compensation

Share-Based Compensation	3 Months Ended
	Mar. 31, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-Based Compensation	Share-Based Compensation
	For the three months ended March 31, 2015 and 2014, we recorded share-based compensation and related tax benefits as follows:
		Three months ended March 31,
	(Dollars in thousands)	2015				2014
	Share-based compensation expense	$	7,771			$	7,078
	Income tax benefit related to share-based compensation expense	(2,638		)		(2,160		)
	Unrecognized Compensation Expense
	As of March 31, 2015, unrecognized share-based compensation expense was as follows:
	(Dollars in thousands)	Unrecognized				Average
		Expense				Expected
						Recognition
						Period - in Years
	Stock options	$	12,436			2.39
	Restricted stock units	32,100				2.4
	Total unrecognized share-based compensation expense	$	44,536
	Share-Based Payment Award Activity
	The table below provides stock option information related to the 2006 Equity Incentive Plan for the three months ended March 31, 2015:
		Options			Weighted				Weighted Average Remaining Contractual Life in Years	Aggregate
					Average					Intrinsic Value
					Exercise Price					of In-The-
										Money
										Options
	Outstanding at December 31, 2014	1,394,888			$	66.03
	Granted	6,718			120.46
	Exercised	(140,880	)		48.97
	Forfeited	(12,400	)		82.72
	Outstanding at March 31, 2015	1,248,326			68.08				4.06	$	73,596,215
	Vested and expected to vest at March 31, 2015	1,213,499			67.45				4.01	72,313,282
	Exercisable at March 31, 2015	554,601			51.32				2.84	41,996,945
	The aggregate intrinsic value of outstanding options shown in the table above represents the pretax intrinsic value based on our closing stock price of $127.04 as of March 31, 2015. The total intrinsic value of options exercised during the three months ended March 31, 2015 was $10.2 million and $7.2 million for the comparable 2014 period.
	The table below provides information for restricted stock units under the 2006 Equity Incentive Plan for the three months ended March 31, 2015:
		Shares			Weighted Average Grant Date Fair Value
	Nonvested at December 31, 2014	614,666			$	79.92
	Granted	53,219			125.99
	Vested	(4,613	)		71.69
	Forfeited	(9,994	)		80.52
	Nonvested at March 31, 2015	653,278			83.73

Cash_and_Cash_Equivalents

Cash and Cash Equivalents	3 Months Ended
	Mar. 31, 2015
Cash and Cash Equivalents [Abstract]
Cash and Cash Equivalents	Cash and Cash Equivalents
	The following table details our cash and cash equivalents at March 31, 2015 and December 31, 2014:
	(Dollars in thousands)		31-Mar-15		31-Dec-14
	Cash and due from banks (1)		$	1,066,854	$	1,694,329
	Securities purchased under agreements to resell (2)		236,027		95,611
	Other short-term investment securities		5,122		6,122
	Total cash and cash equivalents		$	1,308,003	$	1,796,062
	-1	At March 31, 2015 and December 31, 2014, $236 million and $861 million, respectively, of our cash and due from banks was deposited at the Federal Reserve Bank and was earning interest at the Federal Funds target rate, and interest-earning deposits in other financial institutions were $460 million and $440 million, respectively.
	-2	At March 31, 2015 and December 31, 2014, securities purchased under agreements to resell were collateralized by U.S. Treasury securities and U.S. agency securities with aggregate fair values of $244 million and $98 million, respectively. None of these securities received as collateral were sold or pledged as of March 31, 2015 or December 31, 2014.

Investment_Securities

Investment Securities	3 Months Ended
	Mar. 31, 2015
Investments, Debt and Equity Securities [Abstract]
Investment Securities	Investment Securities
	Our investment securities portfolio consists of an available-for-sale securities portfolio and a held-to-maturity securities portfolio, both of which represent interest-earning investment securities, and a non-marketable and other securities portfolio, which primarily represents investments managed as part of our funds management business.
	Available-for-Sale Securities
	The components of our available-for-sale investment securities portfolio at March 31, 2015 and December 31, 2014 are as follows:
			31-Mar-15
	(Dollars in thousands)		Amortized			Unrealized				Unrealized				Carrying
			Cost			Gains				Losses				Value
	Available-for-sale securities, at fair value:
	U.S. treasury securities		$	7,842,942		$	71,447			$	(264	)		$	7,914,125
	U.S. agency debentures		3,271,203			43,675				(1,214		)		3,313,664
	Residential mortgage-backed securities:
	Agency-issued collateralized mortgage obligations—fixed rate		1,769,610			15,005				(6,460		)		1,778,155
	Agency-issued collateralized mortgage obligations—variable rate		733,999			5,207				(3		)		739,203
	Equity securities		1,948			121				(293		)		1,776
	Total available-for-sale securities		$	13,619,702		$	135,455			$	(8,234	)		$	13,746,923
			31-Dec-14
	(Dollars in thousands)		Amortized			Unrealized				Unrealized				Carrying
			Cost			Gains				Losses				Value
	Available-for-sale securities, at fair value:
	U.S. treasury securities		$	7,289,135		$	17,524			$	(4,386	)		$	7,302,273
	U.S. agency debentures		3,540,055			30,478				(8,977		)		$	3,561,556
	Residential mortgage-backed securities:
	Agency-issued collateralized mortgage obligations—fixed rate		1,884,450			14,851				(14,458		)		1,884,843
	Agency-issued collateralized mortgage obligations—variable rate		779,103			5,372				—				784,475
	Equity securities		5,202			2,628				(322		)		7,508
	Total available-for-sale securities		$	13,497,945		$	70,853			$	(28,143	)		$	13,540,655
	The following table summarizes our unrealized losses on our available-for-sale securities portfolio into categories of less than 12 months and 12 months or longer as of March 31, 2015:
			31-Mar-15
			Less than 12 months							12 months or longer								Total
	(Dollars in thousands)		Fair Value of			Unrealized				Fair Value of				Unrealized				Fair Value of				Unrealized
			Investments			Losses				Investments				Losses				Investments				Losses
	Available-for-sale securities:
	U.S. treasury securities		$	176,467		$	(264	)		$	—			$	—			$	176,467			$	(264	)
	U.S. agency debentures		390,034			(1,214		)		—				—				390,034				(1,214		)
	Residential mortgage-backed securities:
	Agency-issued mortgage-backed securities		—			—				—				—				—				—
	Agency-issued collateralized mortgage obligations—fixed rate		244,285			(244		)		428,635				(6,216		)		672,920				(6,460		)
	Agency-issued collateralized mortgage obligations—variable rate		934			(3		)		—				—				934				(3		)
	Equity securities		1,381			(293		)		—				—				1,381				(293		)
	Total temporarily impaired securities: (1)		$	813,101		$	(2,018	)		$	428,635			$	(6,216	)		$	1,241,736			$	(8,234	)
	-1	As of March 31, 2015, we identified a total of 51 investments that were in unrealized loss positions, of which 17 investments totaling $428.6 million with unrealized losses of $6.2 million have been in an impaired position for a period of time greater than 12 months. As of March 31, 2015, we do not intend to sell any impaired fixed income investment securities prior to recovery of our adjusted cost basis, and it is more likely than not that we will not be required to sell any of our securities prior to recovery of our adjusted cost basis. Based on our analysis as of March 31, 2015, we deem all impairments to be temporary, and therefore changes in value for our temporarily impaired securities as of the same date are included in other comprehensive income. Market valuations and impairment analyses on assets in the available-for-sale securities portfolio are reviewed and monitored on a quarterly basis.
	The following table summarizes our unrealized losses on our available-for-sale securities portfolio into categories of less than 12 months and 12 months or longer as of December 31, 2014:
			31-Dec-14
			Less than 12 months							12 months or longer								Total
	(Dollars in thousands)		Fair Value of			Unrealized				Fair Value of				Unrealized				Fair Value of				Unrealized
			Investments			Losses				Investments				Losses				Investments				Losses
	Available-for-sale securities:
	U.S. treasury securities		$	2,297,895		$	(4,386	)		$	—			$	—			$	2,297,895			$	(4,386	)
	U.S. agency debentures		249,266			(489		)		507,385				(8,488		)		756,651				(8,977		)
	Residential mortgage-backed securities:
	Agency-issued mortgage-backed securities		—			—				—				—				—				—
	Agency-issued collateralized mortgage obligations—fixed rate		662,092			(3,104		)		453,801				(11,354		)		1,115,893				(14,458		)
	Equity securities		568			(322		)		—				—				568				(322		)
	Total temporarily impaired securities:		$	3,209,821		$	(8,301	)		$	961,186			$	(19,842	)		$	4,171,007			$	(28,143	)
	The following table summarizes the remaining contractual principal maturities and fully taxable equivalent yields on fixed income investment securities classified as available-for-sale as of March 31, 2015. The weighted average yield is computed using the amortized cost of fixed income investment securities, which are reported at fair value. For U.S. treasury securities, the expected maturity is the actual contractual maturity of the notes. Expected remaining maturities for certain U.S. agency debentures may occur earlier than their contractual maturities because the note issuers have the right to call outstanding amounts ahead of their contractual maturity. Expected maturities for mortgage-backed securities may differ significantly from their contractual maturities because mortgage borrowers have the right to prepay outstanding loan obligations with or without penalties. Mortgage-backed securities classified as available-for-sale typically have original contractual maturities from 10 to 30 years whereas expected average lives of these securities tend to be significantly shorter and vary based upon structure and prepayments in lower rate environments.
			31-Mar-15
			Total						One Year							After One Year to							After Five Years to				After
									or Less							Five Years							Ten Years				Ten Years
	(Dollars in thousands)		Carrying			Weighted-			Carrying				Weighted-			Carrying				Weighted-			Carrying		Weighted-		Carrying		Weighted-
			Value			Average			Value				Average			Value				Average			Value		Average		Value		Average
						Yield							Yield							Yield					Yield				Yield
	U.S. treasury securities		$	7,914,125		1.11	%		$	350,203			0.25	%		$	6,925,629			1.09	%		$	638,293	1.9	%	$	—	—	%
	U.S. agency debentures		3,313,664			1.65			835,499				1.8			2,055,046				1.44			423,119		2.36		—		—
	Residential mortgage-backed securities:
Agency-issued collateralized mortgage obligations - fixed rate		1,778,155			1.99			—				—			—				—			651,254		2.58		1,126,901		1.65
Agency-issued collateralized mortgage obligations - variable rate		739,203			0.71			—				—			—				—			—		—		739,203		0.71
Total		$	13,745,147		1.33			$	1,185,702			1.34			$	8,980,675			1.17			$	1,712,666	2.27		$	1,866,104	1.28
Held-to-Maturity Securities
The components of our held-to-maturity investment securities portfolio at March 31, 2015 and December 31, 2014 are as follows:
		31-Mar-15
(Dollars in thousands)		Amortized			Unrealized				Unrealized				Fair Value
		Cost			Gains				Losses
Held-to-maturity securities, at cost:
U.S. agency debentures (1)		$	473,373		$	8,700			$	—			$	482,073
Residential mortgage-backed securities:
Agency-issued mortgage-backed securities		2,693,488			23,143				(501		)		2,716,130
Agency-issued collateralized mortgage obligations—fixed rate		3,553,640			19,339				(6,328		)		3,566,651
Agency-issued collateralized mortgage obligations—variable rate		124,195			337				(5		)		124,527
Agency-issued commercial mortgage-backed securities		888,823			9,023				(498		)		897,348
Municipal bonds and notes		83,278			126				(480		)		82,924
Total held-to-maturity securities		$	7,816,797		$	60,668			$	(7,812	)		$	7,869,653
-1	Consists of pools of Small Business Investment Company debentures issued and guaranteed by the U.S. Small Business Administration, an independent agency of the United States.
		December 31, 2014
(Dollars in thousands)		Amortized			Unrealized				Unrealized				Fair Value
		Cost			Gains				Losses
Held-to-maturity securities, at cost:
U.S. agency debentures (1)		$	405,899		$	4,589			$	(38	)		$	410,450
Residential mortgage-backed securities:
Agency-issued mortgage-backed securities		2,799,923			5,789				(2,320		)		2,803,392
Agency-issued collateralized mortgage obligations—fixed rate		3,185,109			4,521				(14,885		)		3,174,745
Agency-issued collateralized mortgage obligations—variable rate		131,580			371				—				131,951
Agency-issued commercial mortgage-backed securities		814,589			1,026				(3,800		)		811,815
Municipal bonds and notes		83,942			18				(657		)		83,303
Total held-to-maturity securities		$	7,421,042		$	16,314			$	(21,700	)		$	7,415,656
-1	Consists of pools of Small Business Investment Company debentures issued and guaranteed by the U.S. Small Business Administration, an independent agency of the United States.
The following table summarizes our unrealized losses on our held-to-maturity securities portfolio into categories of less than 12 months and 12 months or longer as of March 31, 2015:
		31-Mar-15
		Less than 12 months							12 months or longer								Total
(Dollars in thousands)		Fair Value of			Unrealized				Fair Value of				Unrealized				Fair Value of				Unrealized
		Investments			Losses				Investments				Losses				Investments				Losses
Held-to-maturity securities:
Residential mortgage-backed securities:
Agency-issued mortgage-backed securities		$	52,761		$	(501	)		$	—			$	—			$	52,761			$	(501	)
Agency-issued collateralized mortgage obligations—fixed rate		622,767			(6,328		)		—				—				622,767				(6,328		)
Agency-issued collateralized mortgage obligations—variable rate		8,660			(5		)		—				—				8,660				(5		)
Agency-issued commercial mortgage-backed securities		164,668			(498		)		—				—				164,668				(498		)
Municipal bonds and notes		48,864			(480		)		—				—				48,864				(480		)
Total temporarily impaired securities (1):		$	897,720		$	(7,812	)		$	—			$	—			$	897,720			$	(7,812	)
-1	As of March 31, 2015, we identified a total of 120 investments that were in unrealized loss positions, none of which have been in an impaired position for a period of time greater than 12 months. As of March 31, 2015, we do not intend to sell any impaired fixed income investment securities prior to recovery of our adjusted cost basis, and it is more likely than not that we will not be required to sell any of our securities prior to recovery of our adjusted cost basis, which is consistent with our classification of these securities. Based on our analysis as of March 31, 2015, we deem all impairments to be temporary. Market valuations and impairment analyses on assets in the held-to-maturity securities portfolio are reviewed and monitored on a quarterly basis.
The following table summarizes our unrealized losses on our held-to-maturity securities portfolio into categories of less than 12 months and 12 months or longer as of December 31, 2014:
		31-Dec-14
		Less than 12 months							12 months or longer (1)								Total
(Dollars in thousands)		Fair Value of			Unrealized				Fair Value of				Unrealized				Fair Value of				Unrealized
		Investments			Losses				Investments				Losses				Investments				Losses
Held-to-maturity securities:
U.S. agency debentures		$	48,335		$	(38	)		$	—			$	—			$	48,335			$	(38	)
Residential mortgage-backed securities:
Agency-issued mortgage-backed securities		999,230			(2,320		)		—				—				999,230				(2,320		)
Agency-issued collateralized mortgage obligations—fixed rate		1,682,348			(9,705		)		783,558				(5,180		)		2,465,906				(14,885		)
Agency-issued commercial mortgage-backed securities		629,840			(3,800		)		—				—				629,840				(3,800		)
Municipal bonds and notes		79,141			(657		)		—				—				79,141				(657		)
Total temporarily impaired securities:		$	3,438,894		$	(16,520	)		$	783,558			$	(5,180	)		$	4,222,452			$	(21,700	)
-1	Represents securities in an unrealized loss position for twelve months or longer in which the amortized cost basis was re-set for those securities re-designated from AFS to HTM effective June 1, 2014.
The following table summarizes the remaining contractual principal maturities and fully taxable equivalent yields on fixed income investment securities classified as held-to-maturity as of March 31, 2015. Interest income on certain municipal bonds and notes (non-taxable investments) are presented on a fully taxable equivalent basis using the federal statutory tax rate of 35%. The weighted average yield is computed using the amortized cost of fixed income investment securities, which are reported at fair value. Expected remaining maturities for certain U.S. agency debentures may occur earlier than their contractual maturities because the note issuers have the right to call outstanding amounts ahead of their contractual maturity. Expected maturities for mortgage-backed securities may differ significantly from their contractual maturities because mortgage borrowers have the right to prepay outstanding loan obligations with or without penalties. Mortgage-backed securities classified as held-to-maturity typically have original contractual maturities from 10 to 30 years whereas expected average lives of these securities tend to be significantly shorter and vary based upon structure and prepayments in lower rate environments.
		31-Mar-15
		Total						One Year							After One Year to							After Five Years to				After
								or Less							Five Years							Ten Years				Ten Years
(Dollars in thousands)		Amortized Cost			Weighted-			Amortized Cost				Weighted-			Amortized Cost				Weighted-			Amortized Cost		Weighted-		Amortized Cost		Weighted-
					Average							Average							Average					Average				Average
					Yield							Yield							Yield					Yield				Yield
U.S. agency debentures		$	473,373		2.69	%		$	—			—	%		$	—			—	%		$	473,373	2.69	%	$	—	—	%
Residential mortgage-backed securities:
Agency-issued mortgage-backed securities		2,693,488			2.42			—				—			42,382				2.38			794,716		2.23		1,856,390		2.51
Agency-issued collateralized mortgage obligations - fixed rate		3,553,640			1.65			—				—			—				—			—		—		3,553,640		1.65
Agency-issued collateralized mortgage obligations - variable rate		124,195			0.65			—				—			—				—			—		—		124,195		0.65
Agency-issued commercial mortgage-backed securities		888,823			2.16			—				—			—				—			—		—		888,823		2.16
Municipal bonds and notes		83,278			6			3,442				5.39			33,261				5.87			40,081		6.11		6,494		6.34
Total		$	7,816,797		2.07			$	3,442			5.39			$	75,643			3.91			$	1,308,170	2.52		$	6,429,542	1.95
Non-marketable and Other Securities
The components of our non-marketable and other investment securities portfolio at March 31, 2015 and December 31, 2014 are as follows:
(Dollars in thousands)		31-Mar-15			31-Dec-14
Non-marketable and other securities:
Non-marketable securities (fair value accounting):
Venture capital and private equity fund investments (1)		$	1,195,303		$	1,130,882
Other venture capital investments (2)		78,850			71,204
Other securities (fair value accounting) (3)		11,936			108,251
Non-marketable securities (equity method accounting):
Other investments (4)		145,942			142,674
Non-marketable securities (cost method accounting):
Venture capital and private equity fund investments (5)		134,575			140,551
Other investments (6)		14,910			13,423
Investments in qualified affordable housing projects (6)		125,357			121,155
Total non-marketable and other securities		$	1,706,873		$	1,728,140
-1	The following table shows the amounts of venture capital and private equity fund investments held by the following consolidated funds and our ownership percentage of each fund at March 31, 2015 and December 31, 2014 (fair value accounting):
		31-Mar-15						31-Dec-14
(Dollars in thousands)		Amount			Ownership %			Amount				Ownership %
SVB Strategic Investors Fund, LP		$	23,953		12.6	%		$	24,645			12.6	%
SVB Strategic Investors Fund II, LP		89,219			8.6			97,250				8.6
SVB Strategic Investors Fund III, LP		257,539			5.9			269,821				5.9
SVB Strategic Investors Fund IV, LP		297,752			5			291,291				5
Strategic Investors Fund V Funds		260,292			Various			226,111				Various
Strategic Investors Fund VI Funds		127,721			—			89,605				—
Strategic Investors Fund VII Funds		2,212			—			—				—
SVB Capital Preferred Return Fund, LP		64,417			20			62,110				20
SVB Capital—NT Growth Partners, LP		64,078			33			61,973				33
SVB Capital Partners II, LP (i)		346			5.1			302				5.1
Other private equity fund (ii)		7,774			58.2			7,774				58.2
Total venture capital and private equity fund investments		$	1,195,303					$	1,130,882
(i)	At March 31, 2015, we had a direct ownership interest of 1.3 percent and an indirect ownership interest of 3.8 percent in the fund through our ownership interest of SVB Strategic Investors Fund II, LP.
(ii)	At March 31, 2015, we had a direct ownership interest of 41.5 percent and indirect ownership interests of 12.6 percent and 4.1 percent in the fund through our ownership interest of SVB Capital—NT Growth Partners, LP and SVB Capital Preferred Return Fund, LP, respectively.
-2	The following table shows the amounts of other venture capital investments held by the following consolidated funds and our ownership percentage of each fund at March 31, 2015 and December 31, 2014 (fair value accounting):
		31-Mar-15						31-Dec-14
(Dollars in thousands)		Amount			Ownership %			Amount				Ownership %
Silicon Valley BancVentures, LP		$	3,390		10.7	%		$	3,291			10.7	%
SVB Capital Partners II, LP (i)		27,215			5.1			20,481				5.1
Capital Partners III, LP		41,055			—			41,055				—
SVB Capital Shanghai Yangpu Venture Capital Fund		7,190			6.8			6,377				6.8
Total other venture capital investments		$	78,850					$	71,204
(i)	At March 31, 2015, we had a direct ownership interest of 1.3 percent and an indirect ownership interest of 3.8 percent in the fund through our ownership of SVB Strategic Investors Fund II, LP.
-3	Investments classified as other securities (fair value accounting) represent direct equity investments in public companies held by our consolidated funds. At December 31, 2014, the amount primarily included total unrealized gains in one public company, FireEye, Inc. ("FireEye"). During the first quarter of 2015, our managed direct venture funds distributed the remaining 2.5 million shares of FireEye common stock to their respective investors (including the Company), resulting in $15.9 million of realized gains on investment securities ($3.3 million net of noncontrolling interests but inclusive of the Company's carried interests). As of March 31, 2015, we no longer hold any shares of FireEye common stock, either directly or through our managed direct venture funds.
-4	The following table shows the carrying value and our ownership percentage of each investment at March 31, 2015 and December 31, 2014 (equity method accounting):
		31-Mar-15						31-Dec-14
(Dollars in thousands)		Amount			Ownership %			Amount				Ownership %
Gold Hill Capital 2008, LP (i)		$	22,040		15.5	%		$	21,294			15.5	%
China Joint Venture investment		79,695			50			79,569				50
Other investments		44,207			Various			41,811				Various
Total other investments (equity method accounting)		$	145,942					$	142,674
(i)	At March 31, 2015, we had a direct ownership interest of 11.5 percent in the fund and an indirect interest in the fund through our investment in Gold Hill Capital 2008, LLC of 4.0 percent.
-5	Represents investments in 277 and 281 funds (primarily venture capital funds) at March 31, 2015 and December 31, 2014, respectively, where our ownership interest is typically less than 5% of the voting interests of each such fund and in which we do not have the ability to exercise significant influence over the partnerships operating activities and financial policies. The carrying value, and estimated fair value, of these venture capital and private equity fund investments (cost method accounting) was $135 million, and $238 million, respectively, as of March 31, 2015. The carrying value, and estimated fair value, of these venture capital and private equity fund investments (cost method accounting) was $141 million and $234 million, respectively, as of December 31, 2014.
-6	Prior period amounts have been revised to reflect the retrospective application of new accounting guidance adopted in the first quarter of 2015 related to our investments in qualified affordable housing projects (ASU 2014-01). See Note 1 - "Basis of Presentation" of the "Notes to Interim Consolidated Financial Statements" under Part I, Item 1 in this report.
The following table presents the components of gains and losses (realized and unrealized) on investment securities for the three months ended March 31, 2015 and 2014:
		Three months ended March 31,
(Dollars in thousands)		2015			2014
Gross gains on investment securities:
Available-for-sale securities, at fair value (1)		$	2,690		$	373
Non-marketable securities (fair value accounting):
Venture capital and private equity fund investments		58,489			111,436
Other venture capital investments		6,450			2,582
Other securities (fair value accounting)		19,601			116,750
Non-marketable securities (equity method accounting):
Other investments		4,188			3,642
Non-marketable securities (cost method accounting):
Venture capital and private equity fund investments		4,833			3,303
Other investments		358			134
Total gross gains on investment securities		96,609			238,220
Gross losses on investment securities:
Available-for-sale securities, at fair value (1)		(94		)	(313		)
Non-marketable securities (fair value accounting):
Venture capital and private equity fund investments		(11,635		)	(101		)
Other venture capital investments		—			(744		)
Other securities (fair value accounting)		(994		)	(12,773		)
Non-marketable securities (equity method accounting):
Other investments		(588		)	(212		)
Non-marketable securities (cost method accounting):
Venture capital and private equity fund investments (2)		(134		)	(156		)
Other investments		(5		)	(9		)
Total gross losses on investment securities		(13,450		)	(14,308		)
Gains on investment securities, net		$	83,159		$	223,912
-1	Includes realized gains (losses) on sales of available-for-sale equity securities that are recognized in the income statement. Unrealized gains (losses) on available-for-sale fixed income and equity securities are recognized in other comprehensive income. The cost basis of available-for-sale securities sold is determined on a specific identification basis.
-2	For the three months ended March 31, 2015 and 2014, includes OTTI losses of $0.1 million from the declines in value for 9 of the 277 investments and $0.1 million from the declines in value for 7 of the 282 investments, respectively. We concluded that any declines in value for the remaining investments were temporary, and as such, no OTTI was required to be recognized.

Loans_and_Allowance_for_Loan_L

Loans and Allowance for Loan Losses	3 Months Ended
	Mar. 31, 2015
Receivables [Abstract]
Loans and Allowance for Loan Losses	Loans and Allowance for Loan Losses
	We serve a variety of clients in the technology and life science & healthcare industries. Our technology clients tend to be in the industries of: hardware (such as semiconductors, communications, data storage, and electronics); software and internet (such as infrastructure software, applications, software services, digital content and advertising technology), and energy and resource innovation ("ERI"). Because of the diverse nature of ERI products and services, for our loan-related reporting purposes, ERI-related loans are reported under hardware and software, as applicable. Our life science & healthcare clients primarily tend to be in the industries of biotechnology, medical devices, healthcare information technology and healthcare services. Loans made to private equity/venture capital firm clients typically enable them to fund investments prior to their receipt of funds from capital calls. Loans to the premium wine industry focus on vineyards and wineries that produce grapes and wines of high quality.
	In addition to commercial loans, we make consumer loans through SVB Private Bank and provide real estate secured loans to eligible employees through our EHOP. Our private banking clients are primarily private equity/venture capital professionals and executive leaders in the innovation companies they support. These products and services include real estate secured home equity lines of credit, which may be used to finance real estate investments and loans used to purchase, renovate or refinance personal residences. These products and services also include restricted stock purchase loans and capital call lines of credit.
	We also provide community development loans made as part of our responsibilities under the Community Reinvestment Act. These loans are included within “Construction loans” below and are primarily secured by real estate.
	The composition of loans, net of unearned income of $107 million and $104 million at March 31, 2015 and December 31, 2014, respectively, is presented in the following table:
	(Dollars in thousands)		31-Mar-15		31-Dec-14
	Commercial loans:
	Software and internet		$	4,871,574	$	4,954,676
	Hardware		1,067,386		1,131,006
	Private equity/venture capital		4,508,670		4,582,906
	Life science & healthcare		1,399,449		1,289,904
	Premium wine		186,070		187,568
	Other		289,010		234,551
	Total commercial loans		12,322,159		12,380,611
	Real estate secured loans:
	Premium wine (1)		613,114		606,753
	Consumer loans (2)		1,209,153		1,118,115
	Other		39,422		39,651
	Total real estate secured loans		1,861,689		1,764,519
	Construction loans		85,684		78,626
	Consumer loans		170,042		160,520
	Total loans, net of unearned income (3)		$	14,439,574	$	14,384,276
	-1	Included in our premium wine portfolio are gross construction loans of $108 million and $112 million at March 31, 2015 and December 31, 2014, respectively.
	-2	Consumer loans secured by real estate at March 31, 2015 and December 31, 2014 were comprised of the following:
	(Dollars in thousands)		31-Mar-15		31-Dec-14
	Loans for personal residence		$	1,001,125	$	918,629
	Loans to eligible employees		139,761		133,568
	Home equity lines of credit		68,267		65,918
	Consumer loans secured by real estate		$	1,209,153	$	1,118,115
	-3	Included within our total loan portfolio are credit card loans of $154 million and $131 million at March 31, 2015 and December 31, 2014, respectively.
	Credit Quality
	The composition of loans, net of unearned income of $107 million and $104 million at March 31, 2015 and December 31, 2014, respectively, broken out by portfolio segment and class of financing receivable, is as follows:
	(Dollars in thousands)		March 31, 2015		December 31, 2014
	Commercial loans:
	Software and internet		$	4,871,574	$	4,954,676
	Hardware		1,067,386		1,131,006
	Private equity/venture capital		4,508,670		4,582,906
	Life science & healthcare		1,399,449		1,289,904
	Premium wine		799,184		794,321
	Other		414,116		352,828
	Total commercial loans		13,060,379		13,105,641
	Consumer loans:
	Real estate secured loans		1,209,153		1,118,115
	Other consumer loans		170,042		160,520
	Total consumer loans		1,379,195		1,278,635
	Total loans, net of unearned income		$	14,439,574	$	14,384,276
	The following table summarizes the aging of our gross loans, broken out by portfolio segment and class of financing receivable as of March 31, 2015 and December 31, 2014:
	(Dollars in thousands)		30 - 59		60 - 89			Greater		Total Past			Current		Loans Past Due
			Days Past		Days Past			Than 90		Due					90 Days or
			Due		Due			Days Past							More Still
								Due							Accruing
															Interest
	March 31, 2015:
	Commercial loans:
	Software and internet		$	1,970	$	162		$	160	$	2,292		$	4,876,739	$	160
	Hardware		298		9,219			—		9,517			1,066,598		—
	Private equity/venture capital		11,462		—			—		11,462			4,536,175		—
	Life science & healthcare		3,768		—			1,689		5,457			1,405,856		1,689
	Premium wine		—		—			—		—			800,197		—
	Other		1,074		—			—		1,074			410,752		—
	Total commercial loans		18,572		9,381			1,849		29,802			13,096,317		1,849
	Consumer loans:
	Real estate secured loans		415		—			1,250		1,665			1,206,762		1,250
	Other consumer loans		410		625			—		1,035			168,782		—
Total consumer loans		825		625			1,250		2,700			1,375,544		1,250
Total gross loans excluding impaired loans		19,397		10,006			3,099		32,502			14,471,861		3,099
Impaired loans		313		5,855			21,920		28,088			14,294		—
Total gross loans		$	19,710	$	15,861		$	25,019	$	60,590		$	14,486,155	$	3,099
December 31, 2014:
Commercial loans:
Software and internet		$	10,989	$	1,627		$	52	$	12,668		$	4,950,291	$	52
Hardware		13,424		126			—		13,550			1,124,423		—
Private equity/venture capital		40,773		—			—		40,773			4,580,526		—
Life science & healthcare		738		786			—		1,524			1,298,728		—
Premium wine		—		—			—		—			795,345		—
Other		178		3			—		181			354,939		—
Total commercial loans		66,102		2,542			52		68,696			13,104,252		52
Consumer loans:
Real estate secured loans		1,592		341			1,250		3,183			1,114,286		1,250
Other consumer loans		—		—			—		—			160,212		—
Total consumer loans		1,592		341			1,250		3,183			1,274,498		1,250
Total gross loans excluding impaired loans		67,694		2,883			1,302		71,879			14,378,750		1,302
Impaired loans		598		1,293			22,320		24,211			13,926		—
Total gross loans		$	68,292	$	4,176		$	23,622	$	96,090		$	14,392,676	$	1,302
The following table summarizes our impaired loans as they relate to our allowance for loan losses, broken out by portfolio segment and class of financing receivable as of March 31, 2015 and December 31, 2014:
(Dollars in thousands)		Impaired loans for		Impaired loans for			Total carrying value of impaired loans		Total unpaid
		which there is a		which there is no					principal of impaired loans
		related allowance		related allowance
		for loan losses		for loan losses
March 31, 2015:
Commercial loans:
Software and internet		$	34,716	$	—		$	34,716	$	35,027
Hardware		510		—			510		525
Private equity/venture capital		—		—			—		—
Life science & healthcare		250		—			250		2,453
Premium wine		—		1,270			1,270		1,734
Other		5,356		—			5,356		5,360
Total commercial loans		40,832		1,270			42,102		45,099
Consumer loans:
Real estate secured loans		30		180			210		1,438
Other consumer loans		70		—			70		254
Total consumer loans		100		180			280		1,692
Total		$	40,932	$	1,450		$	42,382	$	46,791
December 31, 2014:
Commercial loans:
Software and internet		$	33,287	$	—		$	33,287	$	34,218
Hardware		1,403		1,118			2,521		2,535
Private equity/venture capital		—		—			—		—
Life science & healthcare		475		—			475		2,453
Premium wine		—		1,304			1,304		1,743
Other		233		—			233		233
Total commercial loans		35,398		2,422			37,820		41,182
Consumer loans:
Real estate secured loans		—		192			192		1,412
Other consumer loans		125		—			125		305
Total consumer loans		125		192			317		1,717
Total		$	35,523	$	2,614		$	38,137	$	42,899
The following table summarizes our average impaired loans, broken out by portfolio segment and class of financing receivable for the three months ended March 31, 2015 and 2014:
		Three months ended March 31,
(Dollars in thousands)		2015		2014
Average impaired loans:
Commercial loans:
Software and internet		$	33,725	$	14,677
Hardware		1,643		16,020
Life science & healthcare		400		1,022
Premium wine		1,282		1,433
Other		2,139		1,777
Total commercial loans		39,189		34,929
Consumer loans:
Real estate secured loans		195		237
Other consumer loans		88		489
Total consumer loans		283		726
Total average impaired loans		$	39,472	$	35,655
The following tables summarize the activity relating to our allowance for loan losses for the three months ended March 31, 2015 and 2014, broken out by portfolio segment:
Three months ended March 31, 2015 (dollars in thousands)		Beginning Balance December 31, 2014		Charge-offs			Recoveries		Provision for			Ending Balance March 31, 2015
									(Reduction of) Loan Losses
Commercial loans:
Software and internet		$	80,981	$	(1,403	)	$	447	$	2,067		$	82,092
Hardware		25,860		(3,210		)	928		(2,320		)	21,258
Private equity/venture capital		27,997		—			—		2,840			30,837
Life science & healthcare		15,208		(225		)	34		306			15,323
Premium wine		4,473		—			—		30			4,503
Other		3,253		(649		)	10		3,537			6,151
Total commercial loans		157,772		(5,487		)	1,419		6,460			160,164
Consumer loans		7,587		—			132		(8		)	7,711
Total allowance for loan losses		$	165,359	$	(5,487	)	$	1,551	$	6,452		$	167,875
Three months ended March 31, 2014 (dollars in thousands)		Beginning Balance December 31, 2013		Charge-offs			Recoveries		Provision for			Ending Balance March 31, 2014
									(Reduction of) Loan Losses
Commercial loans:
Software and internet		$	64,084	$	(8,010	)	$	114	$	(947	)	$	55,241
Hardware		36,553		(12,175		)	775		83			25,236
Private equity/venture capital		16,385		—			—		1,291			17,676
Life science & healthcare		11,926		(681		)	98		131			11,474
Premium wine		3,914		—			219		(396		)	3,737
Other		3,680		(284		)	—		645			4,041
Total commercial loans		136,542		(21,150		)	1,206		807			117,405
Consumer loans		6,344		—			106		(313		)	6,137
Total allowance for loan losses		$	142,886	$	(21,150	)	$	1,312	$	494		$	123,542
The following table summarizes the allowance for loan losses individually and collectively evaluated for impairment as of March 31, 2015 and December 31, 2014, broken out by portfolio segment:
		31-Mar-15										31-Dec-14
		Individually Evaluated for					Collectively Evaluated for					Individually Evaluated for				Collectively Evaluated for
		Impairment					Impairment					Impairment				Impairment
(Dollars in thousands)		Allowance for loan losses		Recorded investment in loans			Allowance for loan losses		Recorded investment in loans			Allowance for loan losses		Recorded investment in loans		Allowance for loan losses		Recorded investment in loans
Commercial loans:
Software and internet		$	20,942	$	34,716		$	61,150	$	4,836,858		$	13,695	$	33,287	$	67,286	$	4,921,389
Hardware		12		510			21,246		1,066,876			1,133		2,521		24,727		1,128,485
Private equity/venture capital		—		—			30,837		4,508,670			—		—		27,997		4,582,906
Life science & healthcare		63		250			15,260		1,399,199			121		475		15,087		1,289,429
Premium wine		—		1,270			4,503		797,914			—		1,304		4,473		793,017
Other		2,705		5,356			3,446		408,760			71		233		3,182		352,595
Total commercial loans		23,722		42,102			136,442		13,018,277			15,020		37,820		142,752		13,067,821
Consumer loans		100		280			7,611		1,378,915			31		317		7,556		1,278,318
Total		$	23,822	$	42,382		$	144,053	$	14,397,192		$	15,051	$	38,137	$	150,308	$	14,346,139
Credit Quality Indicators
For each individual client, we establish an internal credit risk rating for that loan, which is used for assessing and monitoring credit risk as well as performance of the loan and the overall portfolio. Our internal credit risk ratings are also used to summarize the risk of loss due to failure by an individual borrower to repay the loan. For our internal credit risk ratings, each individual loan is given a risk rating of 1 through 10. Loans risk-rated 1 through 4 are performing loans and translate to an internal rating of “Pass”, with loans risk-rated 1 being cash secured. Loans risk-rated 5 through 7 are performing loans, however, we consider them as demonstrating higher risk, which requires more frequent review of the individual exposures; these translate to an internal rating of “Performing (Criticized)”. A majority of our Performing (Criticized) loans are from our SVB Accelerator practice, serving our emerging or early stage clients. Loans risk-rated 8 and 9 are loans that are considered to be impaired and are on nonaccrual status. (For further description of nonaccrual loans, refer to Note 2—“Summary of Significant Accounting Policies” under Part II, Item 8 of our 2014 Form 10-K). Loans rated 10 are charged-off and are not included as part of our loan portfolio balance. We review our credit quality indicators for performance and appropriateness of risk ratings as part of our evaluation process for our allowance for loan losses.
The following table summarizes the credit quality indicators, broken out by portfolio segment and class of financing receivables as of March 31, 2015 and December 31, 2014:
(Dollars in thousands)		Pass		Performing			Impaired		Total
				(Criticized)
March 31, 2015:
Commercial loans:
Software and internet		$	4,483,199	$	395,832		$	34,716	$	4,913,747
Hardware		874,295		201,820			510		1,076,625
Private equity/venture capital		4,543,600		4,037			—		4,547,637
Life science & healthcare		1,282,275		129,038			250		1,411,563
Premium wine		780,710		19,487			1,270		801,467
Other		404,481		7,345			5,356		417,182
Total commercial loans		12,368,560		757,559			42,102		13,168,221
Consumer loans:
Real estate secured loans		1,199,907		8,520			210		1,208,637
Other consumer loans		165,914		3,903			70		169,887
Total consumer loans		1,365,821		12,423			280		1,378,524
Total gross loans		$	13,734,381	$	769,982		$	42,382	$	14,546,745
December 31, 2014:
Commercial loans:
Software and internet		$	4,611,253	$	351,706		$	33,287	$	4,996,246
Hardware		945,998		191,975			2,521		1,140,494
Private equity/venture capital		4,615,231		6,068			—		4,621,299
Life science & healthcare		1,165,266		134,986			475		1,300,727
Premium wine		774,962		20,383			1,304		796,649
Other		346,153		8,967			233		355,353
Total commercial loans		12,458,863		714,085			37,820		13,210,768
Consumer loans:
Real estate secured loans		1,112,396		5,073			192		1,117,661
Other consumer loans		158,162		2,050			125		160,337
Total consumer loans		1,270,558		7,123			317		1,277,998
Total gross loans		$	13,729,421	$	721,208		$	38,137	$	14,488,766
TDRs
As of March 31, 2015 we had nine TDRs with a total carrying value of $10.6 million where concessions have been granted to borrowers experiencing financial difficulties, in an attempt to maximize collection. There were unfunded commitments available for funding of $3.1 million to the clients associated with these TDRs as of March 31, 2015. The following table summarizes our loans modified in TDRs, broken out by portfolio segment and class of financing receivables at March 31, 2015 and December 31, 2014:
(Dollars in thousands)		31-Mar-15		31-Dec-14
Loans modified in TDRs:
Commercial loans:
Software and internet		$	2,707	$	3,784
Hardware		4,510		1,118
Premium wine		1,830		1,891
Other		191		233
Total commercial loans		9,238		7,026
Consumer loans:
Other consumer loans		1,350		125
Total consumer loans		1,350		125
Total		$	10,588	$	7,151
The following table summarizes the recorded investment in loans modified in TDRs, broken out by portfolio segment and class of financing receivable, for modifications made during the three months ended March 31, 2015 and 2014:
		Three months ended March 31,
(Dollars in thousands)		2015		2014
Loans modified in TDRs during the period:
Commercial loans:
Software and internet		$	—	$	9,737
Hardware		4,000		—
Premium wine		—		650
Other		—		1,746
Total commercial loans		4,000		12,133
Consumer loans:
Real estate secured loans		1,280		—
Total consumer loans		1,280		—
Total loans modified in TDRs during the period (1)		$	5,280	$	12,133
-1	There were no partial charge-offs on loans classified as TDRs during the three months ended March 31, 2015 or March 31, 2014.
During the three months ended March 31, 2015, new TDRs of $5.3 million were modified through payment deferrals granted to our clients.
During the three months ended March 31, 2014, new TDRs of $2.8 million and $9.3 million were modified through forgiveness of principal and payment deferrals granted to our clients, respectively.
The related allowance for loan losses for the majority of our TDRs is determined on an individual basis by comparing the carrying value of the loan to the present value of the estimated future cash flows, discounted at the pre-modification contractual interest rate. For certain TDRs, the related allowance for loan losses is determined based on the fair value of the collateral if the loan is collateral dependent.
The following table summarizes the recorded investment in loans modified in TDRs within the previous 12 months that subsequently defaulted during the three months ended March 31, 2015. There were no TDRs modified, which defaulted during the three months ended March 31, 2014.
		Three months ended March 31,
(Dollars in thousands)		2015
TDRs modified within the previous 12 months that defaulted during the period:
Consumer loans:
Real estate secured loans		$	30
Total TDRs modified within the previous 12 months that defaulted in the period		$	30
Charge-offs and defaults on previously restructured loans are evaluated to determine the impact to the allowance for loan losses, if any. The evaluation of these defaults may impact the assumptions used in calculating the reserve on other TDRs and impaired loans as well as management’s overall outlook of macroeconomic factors that affect the reserve on the loan portfolio as a whole. After evaluating the charge-offs and defaults experienced on our TDRs we determined that no change to our reserving methodology was necessary to determine the allowance for loan losses as of March 31, 2015.

Disposal_Assets_HeldforSale

Disposal - Assets Held-for-Sale	3 Months Ended
	Mar. 31, 2015
Discontinued Operations and Disposal Groups [Abstract]
Disposal - Assets Held-for-Sale	Disposal - Assets Held-for-Sale
	The Company entered into a share purchase agreement to sell all of the outstanding capital stock of the Bank’s subsidiary, SVB India Finance Private Limited, a non-banking financial company in India (“SVBIF”) on January 15, 2015. The sale was completed on April 13, 2015. See Note 17 - "Subsequent Events" of the "Notes to Interim Consolidated Financial Statements" under Part I, Item 1 in this report. As a result of the pending sale of SVBIF, the Company classified SVBIF's net assets as held-for-sale as applicable criteria were met. The following table presents the composition of SVBIF assets held-for-sale included in accrued interest receivable and other assets at March 31, 2015 and December 31, 2014:
	(Dollars in thousands)		31-Mar-15		31-Dec-14
	Assets:
	Cash and due from banks		$	2,897	$	3,054
	Securities purchased under agreement to resell and other short-term investments		6,419		11,898
	Net loans		33,276		26,800
	Premises and equipment, net		24		24
	Accrued interest receivable and other assets		10,307		7,163
	Total assets of SVBIF held-for-sale (1)		$	52,923	$	48,939
	Liabilities:
	Other liabilities		4,723		4,686
	Total liabilities of SVBIF held-for-sale (1)		$	4,723	$	4,686
	-1	Net assets of $48.2 million and $44.3 million are included in our Global Commercial Bank operating segment as reported in Note 11—”Segment Reporting” of the “Notes to Interim Consolidated Financial Statements” under Part I, Item 1 of this report.

ShortTerm_Borrowings_and_LongT

Short-Term Borrowings and Long-Term Debt	3 Months Ended
	Mar. 31, 2015
Debt Disclosure [Abstract]
Short-Term Borrowings and Long-Term Debt	Short-Term Borrowings and Long-Term Debt
	The following table represents outstanding short-term borrowings and long-term debt at March 31, 2015 and December 31, 2014:
						Carrying Value
	(Dollars in thousands)		Maturity	Principal value at March 31, 2015		March 31,		December 31,
						2015		2014
	Short-term borrowings:
	Short-term FHLB advances		1-Apr-15	$	60,000	$	60,000	$	—
	Other short-term borrowings		-1	17,766		17,766		7,781
	Total short-term borrowings					$	77,766	$	7,781
	Long-term debt:
	3.50% Senior Notes		29-Jan-25	$	350,000	$	349,710	$	—
	5.375% Senior Notes		15-Sep-20	350,000		348,495		348,436
	6.05% Subordinated Notes (2)		June 1, 2017	45,964		49,910		50,162
	7.0% Junior Subordinated Debentures		October 15, 2033	50,000		54,802		54,845
	Total long-term debt					$	802,917	$	453,443
	-1	Represents cash collateral received from certain counterparties in relation to market value exposures of derivative contracts in our favor, which includes an interest rate swap agreement related to our 6.05% Subordinated Notes.
	-2	At March 31, 2015 and December 31, 2014, included in the carrying value of our 6.05% Subordinated Notes was an interest rate swap valued at $4.3 million and $4.6 million, respectively, related to hedge accounting associated with the notes.
	Interest expense related to long-term debt was $8.0 million for the three months ended March 31, 2015, and $5.8 million for the three months ended March 31, 2014. Interest expense is net of the hedge accounting impact from our interest rate swap agreement related to our 6.05% Subordinated Notes. The weighted average interest rate associated with our short-term borrowings as of March 31, 2015 was 0.19 percent.
	3.50% Senior Notes
	On January 29, 2015, the Company issued $350 million of 3.50% Senior Notes due in January 2025 (“3.50% Senior Notes”). We received net proceeds from this offering of approximately $346.4 million after deducting underwriting discounts and commissions and issuance costs. The balance of our 3.50% Senior Notes at March 31, 2015 was $349.7 million, which is reflective of a $0.3 million discount.
	Available Lines of Credit
	We have certain facilities in place to enable us to access short-term borrowings on a secured (using high-quality fixed income securities as collateral) and an unsecured basis. These include repurchase agreements and uncommitted federal funds lines with various financial institutions. As of March 31, 2015, we did not borrow against our uncommitted federal funds lines. We also pledge securities to the FHLB of San Francisco and the discount window at the Federal Reserve Bank. The market value of collateral pledged to the FHLB of San Francisco (comprised primarily of U.S. agency debentures and mortgage securities) at March 31, 2015 totaled $1.3 billion, $60 million of which was used, with the remaining available to support additional borrowings. The market value of collateral pledged at the discount window of the Federal Reserve Bank at March 31, 2015 totaled $979 million, all of which was unused and available to support additional borrowings.

Derivative_Financial_Instrumen

Derivative Financial Instruments	3 Months Ended
	Mar. 31, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Financial Instruments	Derivative Financial Instruments
	We primarily use derivative financial instruments to manage interest rate risk, currency exchange rate risk, and to assist customers with their risk management objectives. Also, in connection with negotiating credit facilities and certain other services, we often obtain equity warrant assets giving us the right to acquire stock in private, venture-backed companies in the technology and life science & healthcare industries.
	Interest Rate Risk
	Interest rate risk is our primary market risk and can result from timing and volume differences in the repricing of our interest rate-sensitive assets and liabilities and changes in market interest rates. To manage interest rate risk for our 6.05% Subordinated Notes, we entered into a fixed-for-floating interest rate swap agreement at the time of debt issuance based upon LIBOR with matched-terms. Net cash benefits associated with our interest rate swap is recorded as a reduction in “Interest expense—Borrowings,” a component of net interest income. The fair value of our interest rate swaps is calculated using a discounted cash flow method and adjusted for credit valuation associated with counterparty risk. Changes in fair value of the interest rate swaps are reflected in either other assets (for swaps in an asset position) or other liabilities (for swaps in a liability position).
	We assess hedge effectiveness under ASC 815, Derivatives and Hedging, using the long-haul method. Any differences associated with our interest rate swap that arise as a result of hedge ineffectiveness is recorded through net gains on derivative instruments, in noninterest income, a component of consolidated net income.
	Currency Exchange Risk
	We enter into foreign exchange forward contracts to economically reduce our foreign exchange exposure risk associated with the net difference between foreign currency denominated assets and liabilities, primarily in Pound Sterling and Euro. We do not designate any foreign exchange forward contracts as derivative instruments that qualify for hedge accounting. Gains or losses from changes in currency rates on foreign currency denominated instruments are included in other noninterest income, a component of noninterest income. We may experience ineffectiveness in the economic hedging relationship, because the instruments are revalued based upon changes in the currency’s spot rate on the principal value, while the forwards are revalued on a discounted cash flow basis. We record forward agreements in gain positions in other assets and loss positions in other liabilities, while net changes in fair value are recorded through net gains on derivative instruments, in noninterest income, a component of consolidated net income. Additionally, through our global banking operations we maintain customer deposits denominated in the Euro and Pound Sterling, which are used to fund certain loans in these currencies to limit our exposure to currency fluctuations.
	Other Derivative Instruments
	Also included in our derivative instruments are equity warrant assets, loan conversion options, forward and option contracts, and interest rate contracts. For further description of these other derivative instruments, refer to Note 2-“Summary of Significant Accounting Policies" under Part II, Item 8 of our 2014 Form 10-K.
	Counterparty Credit Risk
	We are exposed to credit risk if counterparties to our derivative contracts do not perform as expected. We mitigate counterparty credit risk through credit approvals, limits, monitoring procedures and obtaining collateral, as appropriate. With respect to measuring counterparty credit risk for derivative instruments, we measure the fair value of a group of financial assets and financial liabilities on a net risk basis by counterparty portfolio.
	The total notional or contractual amounts, fair value, collateral and net exposure of our derivative financial instruments at March 31, 2015 and December 31, 2014 were as follows:
					31-Mar-15																31-Dec-14
	(Dollars in thousands)		Balance Sheet		Notional or				Fair Value				Collateral				Net				Notional or				Fair Value			Collateral		Net
			Location		Contractual								-1				Exposure				Contractual							-1		Exposure
					Amount												-2				Amount									-2
	Derivatives designated as hedging instruments:
	Interest rate risks:
	Interest rate swaps		Other assets		$	45,964			$	4,340			$	2,970			$	1,370			$	45,964			$	4,609		$	2,970	$	1,639
	Derivatives not designated as hedging instruments:
	Currency exchange risks:
	Foreign exchange forwards		Other assets		179,467				8,688				5,138				3,550				200,957				5,050			2,441		2,609
	Foreign exchange forwards		Other liabilities		3,916				(677		)		—				(677		)		6,226				(489		)	—		(489		)
	Net exposure								8,011				5,138				2,873								4,561			2,441		2,120
	Other derivative instruments:
	Equity warrant assets		Other assets		198,864				124,456				—				124,456				197,878				116,604			—		116,604
	Other derivatives:
	Client foreign exchange forwards		Other assets		772,019				45,284				9,658				35,626				801,487				28,954			2,370		26,584
	Client foreign exchange forwards		Other liabilities		694,943				(44,527		)		—				(44,527		)		774,355				(27,647		)	—		(27,647		)
	Client foreign currency options		Other assets		51,483				523				—				523				34,926				227			—		227
	Client foreign currency options		Other liabilities		51,483				(523		)		—				(523		)		34,926				(227		)	—		(227		)
	Client interest rate derivatives		Other assets		377,530				2,907				—				2,907				387,410				2,546			—		2,546
	Client interest rate derivatives		Other liabilities		377,530				(3,166		)		—				(3,166		)		387,410				(2,748		)	—		(2,748		)
	Net exposure								498				9,658				(9,160		)						1,105			2,370		(1,265		)
	Net								$	137,305			$	17,766			$	119,539							$	126,879		$	7,781	$	119,098
	-1	Cash collateral received from our counterparties in relation to market value exposures of derivative contracts in our favor is recorded as a component of “short-term borrowings” on our consolidated balance sheets.
	-2	Net exposure for contracts in a gain position reflects the replacement cost in the event of nonperformance by all such counterparties. The credit ratings of our institutional counterparties as of March 31, 2015 remain at investment grade or higher and there were no material changes in their credit ratings during the three months ended March 31, 2015.
	A summary of our derivative activity and the related impact on our consolidated statements of income for the three months ended March 31, 2015 and 2014 is as follows:
					Three months ended March 31,
	(Dollars in thousands)		Statement of income location		2015				2014
	Derivatives designated as hedging instruments:
	Interest rate risks:
	Net cash benefit associated with interest rate swaps		Interest expense—borrowings		$	638			$	639
	Changes in fair value of interest rate swaps		Net gains on derivative instruments		(3		)		(12		)
	Net gains associated with interest rate risk derivatives				$	635			$	627
	Derivatives not designated as hedging instruments:
	Currency exchange risks:
	(Losses) gains on revaluations of foreign currency instruments		Other noninterest income		$	(20,159	)		$	978
	Gains (losses) on internal foreign exchange forward contracts, net		Net gains on derivative instruments		20,018				(1,029		)
	Net losses associated with currency risk				$	(141	)		$	(51	)
	Other derivative instruments:
	Net gains on equity warrant assets		Net gains on derivative instruments		$	20,278			$	25,373
	(Losses) gains on client foreign exchange forward contracts, net		Net gains on derivative instruments		$	(507	)		$	302
	Net losses on other derivatives (1)		Net gains on derivative instruments		$	(57	)		$	(467	)
	-1	Primarily represents the change in fair value of loan conversion options.
	Balance Sheet Offsetting
	Certain of our derivative and other financial instruments are subject to enforceable master netting arrangements with our counterparties. These agreements provide for the net settlement of multiple contracts with a single counterparty through a single payment, in a single currency, in the event of default on or termination of any one contract.
	The following table summarizes our assets subject to enforceable master netting arrangements as of March 31, 2015 and December 31, 2014:
															Gross Amounts Not Offset in the Statement of Financial Position But Subject to Master Netting Arrangements
	(Dollars in thousands)		Gross Amounts of Recognized Assets				Gross Amounts offset in the Statement of Financial Position				Net Amounts of Assets Presented in the Statement of Financial Position				Financial Instruments				Cash Collateral Received				Net Amount
	31-Mar-15
	Derivative Assets:
	Interest rate swaps		$	4,340			$	—			$	4,340			$	(1,370	)		$	(2,970	)		$	—
	Foreign exchange forwards		53,972				—				53,972				(24,627		)		(14,796		)		14,549
Foreign currency options		806				(283		)		523				(253		)		—				270
Client interest rate derivatives		2,907				—				2,907				(2,907		)		—				—
Total derivative assets:		62,025				(283		)		61,742				(29,157		)		(17,766		)		14,819
Reverse repurchase, securities borrowing, and similar arrangements		236,027				—				236,027				(236,027		)		—				—
Total		$	298,052			$	(283	)		$	297,769			$	(265,184	)		$	(17,766	)		$	14,819
31-Dec-14
Derivative Assets:
Interest rate swaps		$	4,609			$	—			$	4,609			$	(1,639	)		$	(2,970	)		$	—
Foreign exchange forwards		34,004				—				34,004				(17,843		)		(4,811		)		11,350
Foreign currency options		501				(274		)		227				(144		)		—				83
Client interest rate derivatives		2,546				—				2,546				(2,546		)		—				—
Total derivative assets:		41,660				(274		)		41,386				(22,172		)		(7,781		)		11,433
Reverse repurchase, securities borrowing, and similar arrangements		95,611				—				95,611				(95,611		)		—				—
Total		$	137,271			$	(274	)		$	136,997			$	(117,783	)		$	(7,781	)		$	11,433
The following table summarizes our liabilities subject to enforceable master netting arrangements as of March 31, 2015 and December 31, 2014:
														Gross Amounts Not Offset in the Statement of Financial Position But Subject to Master Netting Arrangements
(Dollars in thousands)		Gross Amounts of Recognized Liabilities				Gross Amounts offset in the Statement of Financial Position				Net Amounts of Liabilities Presented in the Statement of Financial Position				Financial Instruments				Cash Collateral Pledged				Net Amount
31-Mar-15
Derivative Liabilities:
Foreign exchange forwards		$	45,204			$	—			$	45,204			$	(8,467	)		$	—			$	36,737
Foreign currency options		806				(283		)		523				(270		)		—				253
Client interest rate derivatives		3,166				—				3,166				(3,166		)		—				—
Total derivative liabilities:		49,176				(283		)		48,893				(11,903		)		—				36,990
Repurchase, securities lending, and similar arrangements		—				—				—				—				—				—
Total		$	49,176			$	(283	)		$	48,893			$	(11,903	)		$	—			$	36,990
31-Dec-14
Derivative Liabilities:
Foreign exchange forwards		$	28,136			$	—			$	28,136			$	(16,808	)		$	—			$	11,328
Foreign currency options		501				(274		)		227				(83		)		—				144
Client interest rate derivatives		2,748				—				2,748				(2,748		)		—				—
Total derivative liabilities:		31,385				(274		)		31,111				(19,639		)		—				11,472
Repurchase, securities lending, and similar arrangements		—				—				—				—				—				—
Total		$	31,385			$	(274	)		$	31,111			$	(19,639	)		$	—			$	11,472

Other_Noninterest_Loss_Income_

Other Noninterest (Loss) Income and Other Noninterest Expense	3 Months Ended
	Mar. 31, 2015
Other Income and Expenses [Abstract]
Other Noninterest (Loss) Income and Other Noninterest Expense	Other Noninterest (Loss) Income and Other Noninterest Expense
	A summary of other noninterest (loss) income for the three months ended March 31, 2015 and 2014 is as follows:
			Three months ended March 31,
	(Dollars in thousands)		2015			2014
	Fund management fees		$	3,722		$	2,755
	Service-based fee income		2,150			2,027
	(Losses) gains on revaluation of foreign currency instruments (1)		(20,159		)	978
	Other (2)		5,207			5,440
	Total other noninterest (loss) income		$	(9,080	)	$	11,200
	-1	Represents the revaluation of foreign currency denominated financial instruments issued and held by us, primarily loans, deposits and cash.
	-2	Includes dividends on FHLB/FRB stock, correspondent bank rebate income and other fee income.
	A summary of other noninterest expense for the three months ended March 31, 2015 and 2014 is as follows:
			Three months ended March 31,
	(Dollars in thousands)		2015			2014
	Client services		$	3,549		$	2,359
	Telephone		1,959			1,748
	Data processing services		1,833			2,227
	Postage and supplies		765			769
	Dues and publications		585			497
	Other		4,907			1,562
	Total other noninterest expense (1)		$	13,598		$	9,162
	-1	Prior period amounts have been revised to reflect the retrospective application of new accounting guidance adopted in the first quarter of 2015 related to our investments in qualified affordable housing projects (ASU 2014-01). See Note 1 - "Basis of Presentation" of the "Notes to Interim Consolidated Financial Statements" under Part I, Item 1 in this report.

Segment_Reporting

Segment Reporting	3 Months Ended
	Mar. 31, 2015
Segment Reporting [Abstract]
Segment Reporting	Segment Reporting
	We have three reportable segments for management reporting purposes: Global Commercial Bank, SVB Private Bank and SVB Capital. The results of our operating segments are based on our internal management reporting process.
	Our operating segments’ primary source of revenue is from net interest income, which is primarily the difference between interest earned on loans, net of funds transfer pricing (“FTP”), and interest paid on deposits, net of FTP. Accordingly, our segments are reported using net interest income, net of FTP. FTP is an internal measurement framework designed to assess the financial impact of a financial institution’s sources and uses of funds. It is the mechanism by which an earnings credit is given for deposits raised, and an earnings charge is made for funded loans. FTP is calculated at an instrument level based on account characteristics.
	We also evaluate performance based on provision for loan losses, noninterest income and noninterest expense, which are presented as components of segment operating profit or loss. In calculating each operating segment’s noninterest expense, we consider the direct costs incurred by the operating segment as well as certain allocated direct costs. As part of this review, we allocate certain corporate overhead costs to a corporate account. We do not allocate income taxes to our segments. Additionally, our management reporting model is predicated on average asset balances; therefore, period-end asset balances are not presented for segment reporting purposes. Changes in an individual client’s primary relationship designation have resulted, and in the future may result, in the inclusion of certain clients in different segments in different periods.
	Unlike financial reporting, which benefits from the comprehensive structure provided by GAAP, our internal management reporting process is highly subjective, as there is no comprehensive, authoritative guidance for management reporting. Our management reporting process measures the performance of our operating segments based on our internal operating structure, which is subject to change from time to time, and is not necessarily comparable with similar information for other financial services companies.
	For reporting purposes, SVB Financial Group has three operating segments for which we report our financial information:
	•	Global Commercial Bank is comprised of results from the following:
	◦	Our Commercial Bank products and services are provided by the Bank and its subsidiaries to commercial clients in the technology, life science & healthcare and private equity/venture capital industries. The Bank provides solutions to the financial needs of commercial clients, through credit, global treasury management, foreign exchange, global trade finance, and other services. It serves clients within the United States, as well as non-U.S. clients in key international innovation markets. In addition, the Bank and its subsidiaries offer a variety of investment services and solutions to its clients that enable them to effectively manage their assets.
	◦	Our Private Equity Division provides banking products and services primarily to our private equity and venture capital clients.
	◦	Our Wine practice provides banking products and services to our premium wine industry clients, including vineyard development loans.
	◦	SVB Analytics provides equity valuation services to companies and private equity/venture capital firms.
	◦	Debt Fund Investments is comprised of our investments in certain debt funds in which we are a strategic investor.
	•	SVB Private Bank is the private banking division of the Bank, which provides a range of personal financial solutions for consumers. Our clients are primarily private equity/venture capital professionals and executive leaders of the innovation companies they support. We offer a customized suite of private banking services, including mortgages, home equity lines of credit, restricted stock purchase loans, capital call lines of credit and other secured and unsecured lending, as well as cash and wealth management services.
	•	SVB Capital is the venture capital investment arm of SVBFG, which focuses primarily on funds management. SVB Capital manages funds (primarily venture capital funds) on behalf of third party limited partners and, on a more limited basis, SVB Financial Group. The SVB Capital family of funds is comprised of direct venture funds that invest in companies and funds of funds that invest in other venture capital funds. SVB Capital generates income for the Company primarily from investment returns (including carried interest) and management fees.
	The summary financial results of our operating segments are presented along with a reconciliation to our consolidated interim results.
	Our segment information for the three months ended March 31, 2015 and 2014 is as follows:
	(Dollars in thousands)		Global			SVB Private			SVB Capital (1)			Other Items (2)			Total
			Commercial			Bank
			Bank (1)
	Three months ended March 31, 2015
	Net interest income		$	203,755		$	9,723		$	(24	)	$	25,436		$	238,890
	(Provision for) reduction of loan losses		(6,460		)	8			—			—			(6,452		)
	Noninterest income		64,689			397			21,141			85,791			172,018
	Noninterest expense (3)		(136,282		)	(2,747		)	(3,891		)	(53,188		)	(196,108		)
	Income before income tax expense (4)		$	125,702		$	7,381		$	17,226		$	58,039		$	208,348
	Total average loans, net of unearned income		$	12,729,630		$	1,374,189		$	—		$	(57,450	)	$	14,046,369
	Total average assets (5)		35,962,427			1,921,554			269,982			1,146,626			39,300,589
	Total average deposits		32,472,827			1,251,939			—			133,013			33,857,779
	Three months ended March 31, 2014
	Net interest income		$	175,303		$	6,892		$	14		$	14,119		$	196,328
	(Provision for) reduction of loan losses		(807		)	313			—			—			(494		)
	Noninterest income		58,635			274			37,672			213,644			310,225
	Noninterest expense (3)		(120,706		)	(2,495		)	(2,635		)	(44,572		)	(170,408		)
	Income before income tax expense (4)		$	112,425		$	4,984		$	35,051		$	183,191		$	335,651
	Total average loans, net of unearned income		$	9,677,957		$	1,049,901		$	—		$	39,826		$	10,767,684
	Total average assets (5)		25,504,407			967,873			340,990			954,363			27,767,633
	Total average deposits		22,877,819			745,083			—			53,546			23,676,448
	-1	Global Commercial Bank’s and SVB Capital’s components of net interest income, noninterest income, noninterest expense and total average assets are shown net of noncontrolling interests for all periods presented. Noncontrolling interest is included within "Other Items".
	-2	The "Other Items" column reflects the adjustments necessary to reconcile the results of the operating segments to the consolidated financial statements prepared in conformity with GAAP. Noninterest income is primarily attributable to noncontrolling interests and gains on equity warrant assets. Noninterest expense primarily consists of expenses associated with corporate support functions such as finance, human resources, marketing, legal and other expenses. Additionally, average assets primarily consist of cash and cash equivalents and loans from our Community Development Finance practice as part of our responsibilities under the Community Reinvestment Act.
	-3	The Global Commercial Bank segment includes direct depreciation and amortization of $5.1 million and $4.9 million for the three months ended March 31, 2015 and 2014, respectively.
	-4	The internal reporting model used by management to assess segment performance does not calculate income tax expense by segment. Our effective tax rate is a reasonable approximation of the segment rates.
	-5	Total average assets equal the greater of total average assets or the sum of total liabilities and total stockholders’ equity for each segment.

OffBalance_Sheet_Arrangements_

Off-Balance Sheet Arrangements, Guarantees and Other Commitments	3 Months Ended
	Mar. 31, 2015
Disclosure Off Balance Sheet Arrangements Guarantees And Other Commitments Additional Information [Abstract]
Off-Balance Sheet Arrangements, Guarantees and Other Commitments	Off-Balance Sheet Arrangements, Guarantees and Other Commitments
	In the normal course of business, we use financial instruments with off-balance sheet risk to meet the financing needs of our customers. These financial instruments include commitments to extend credit, commercial and standby letters of credit and commitments to invest in venture capital and private equity fund investments. These instruments involve credit risk to varying degrees. Credit risk is defined as the possibility of sustaining a loss because other parties to the financial instrument fail to perform in accordance with the terms of the contract.
	Commitments to Extend Credit
	The following table summarizes information related to our commitments to extend credit at March 31, 2015 and December 31, 2014:
	(Dollars in thousands)		March 31,		December 31,
			2015		2014
	Loan commitments available for funding: (1)
	Fixed interest rate commitments		$	1,611,025	$	1,591,408
	Variable interest rate commitments		12,618,196		11,860,039
	Total loan commitments available for funding		14,229,221		13,451,447
	Commercial and standby letters of credit (2)		1,256,293		1,254,338
	Total unfunded credit commitments		$	15,485,514	$	14,705,785
	Commitments unavailable for funding (3)		$	1,920,937	$	1,868,489
	Maximum lending limits for accounts receivable factoring arrangements (4)		1,120,763		1,044,548
	Reserve for unfunded credit commitments (5)		38,628		36,419
	-1	Represents commitments which are available for funding, due to clients meeting all collateral, compliance and financial covenants required under loan commitment agreements.
	-2	See below for additional information on our commercial and standby letters of credit.
	-3	Represents commitments which are currently unavailable for funding, due to clients failing to meet all collateral, compliance and financial covenants under loan commitment agreements.
	-4	We extend credit under accounts receivable factoring arrangements when our clients’ sales invoices are deemed creditworthy under existing underwriting practices.
	-5	Our reserve for unfunded credit commitments includes an allowance for both our unfunded loan commitments and our letters of credit.
	Commercial and Standby Letters of Credit
	The table below summarizes our commercial and standby letters of credit at March 31, 2015. The maximum potential amount of future payments represents the amount that could be remitted under letters of credit if there were a total default by the guaranteed parties, without consideration of possible recoveries under recourse provisions or from the collateral held or pledged.
	(Dollars in thousands)		Expires In One		Expires After		Total Amount		Maximum Amount
			Year or Less		One Year		Outstanding		of Future Payments
	Financial standby letters of credit		$	1,137,234	$	57,997	$	1,195,231	$	1,195,231
	Performance standby letters of credit		45,105		6,550		51,655		51,655
	Commercial letters of credit		9,407		—		9,407		9,407
	Total		$	1,191,746	$	64,547	$	1,256,293	$	1,256,293
	Deferred fees related to financial and performance standby letters of credit were $8.2 million at both March 31, 2015 and December 31, 2014. At March 31, 2015, collateral in the form of cash of $509.0 million and available-for-sale securities of $1.5 million were available to us to reimburse losses, if any, under financial and performance standby letters of credit.
	Commitments to Invest in Venture Capital and Private Equity Funds
	We make commitments to invest in venture capital and private equity funds, which in turn make investments generally in, or in some cases make loans to, privately-held companies. Commitments to invest in these funds are generally made for a 10-year period from the inception of the fund. Although the limited partnership agreements governing these investments typically do not restrict the general partners from calling 100% of committed capital in one year, it is customary for these funds to generally call most of the capital commitments over 5 to 7 years; however in certain cases, the funds may not call 100% of committed capital over the life of the fund. The actual timing of future cash requirements to fund these commitments is generally dependent upon the investment cycle, overall market conditions, and the nature and type of industry in which the privately held companies operate. The following table details our total capital commitments, unfunded capital commitments, and our ownership percentage in each fund at March 31, 2015:
	Our Ownership in Venture Capital and Private Equity Funds		SVBFG Capital Commitments		SVBFG Unfunded		SVBFG Ownership
	(Dollars in thousands)				Commitments		of each Fund (4)
	Silicon Valley BancVentures, LP		$	6,000	$	270	10.7	%
	SVB Capital Partners II, LP (1)		1,200		162		5.1
	Capital Partners III, LP		—		—		—
	SVB Capital Shanghai Yangpu Venture Capital Fund		935		—		6.8
	SVB Strategic Investors Fund, LP		15,300		688		12.6
	SVB Strategic Investors Fund II, LP		15,000		1,050		8.6
	SVB Strategic Investors Fund III, LP		15,000		1,275		5.9
	SVB Strategic Investors Fund IV, LP		12,239		2,325		5
	Strategic Investors Fund V Funds		515		178		Various
	Strategic Investors Fund VI Funds		—		—		—
	Strategic Investors Fund VII Funds		—		—		—
	SVB Capital Preferred Return Fund, LP		12,688		—		20
	SVB Capital—NT Growth Partners, LP		24,670		1,340		33
	Other private equity fund (2)		9,338		—		58.2
	Partners for Growth, LP		25,000		9,750		50
	Debt funds (equity method accounting)		63,134		4,950		Various
	Other fund investments (3)		301,172		19,268		Various
	Total		$	502,191	$	41,256
	-1	Our ownership includes direct ownership of 1.3 percent and indirect ownership interest of 3.8 percent through our investment in SVB Strategic Investors Fund II, LP.
	-2	Our ownership includes direct ownership of 41.5 percent and indirect ownership interests of 12.6 percent and 4.1 percent in the fund through our ownership interest of SVB Capital - NT Growth Partners, LP and SVB Capital Preferred Return Fund, LP, respectively.
	-3	Represents commitments to 283 funds (primarily venture capital funds) where our ownership interest is generally less than 5 percent of the voting interests of each such fund.
	-4	We are subject to the Volcker Rule, which restricts or limits us from sponsoring or having ownership interests in “covered” funds including venture capital and private equity funds. See “Business - Supervision and Regulation” under Item 1 of Part I of our 2014 Form 10-K.
	The following table details the amounts of remaining unfunded commitments to venture capital and private equity funds by our consolidated managed funds of funds (including our interest and the noncontrolling interests) at March 31, 2015:
	Limited Partnership		Unfunded
	(Dollars in thousands)		Commitments
	SVB Strategic Investors Fund, LP		$	2,250
	SVB Strategic Investors Fund II, LP		5,021
	SVB Strategic Investors Fund III, LP		11,237
	SVB Strategic Investors Fund IV, LP		32,730
	Strategic Investors Fund V Funds		123,888
	Strategic Investors Fund VI Funds		219,750
Strategic Investors Fund VII Funds		153,919
SVB Capital Preferred Return Fund, LP		4,448
SVB Capital—NT Growth Partners, LP		4,672
Other private equity fund		77
Total		$	557,992

Income_Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2015
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes
	We are subject to income tax in the U.S. federal jurisdiction and various state and foreign jurisdictions and have identified our federal tax return and tax returns in California and Massachusetts as major tax filings. Our U.S. federal tax returns for 2011 and subsequent years remain open to full examination. Our California tax returns for 2010 and subsequent tax years remain open to full examination. Massachusetts tax returns for 2011 and subsequent years remain open to full examination.
	At March 31, 2015, our unrecognized tax benefit was $3.8 million, the recognition of which would reduce our income tax expense by $2.7 million. We do not expect that our unrecognized tax benefit will materially change in the next 12 months.
	We recognize interest and penalties related to income tax matters as part of income before income taxes. Interest and penalties were not material for the three months ended March 31, 2015.

Fair_Value_of_Financial_Instru

Fair Value of Financial Instruments	3 Months Ended
	Mar. 31, 2015
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	Fair Value of Financial Instruments
	Fair Value Measurements
	Our available-for-sale securities, derivative instruments and certain non-marketable and other securities are financial instruments recorded at fair value on a recurring basis. We make estimates regarding valuation of assets and liabilities measured at fair value in preparing our interim consolidated financial statements.
	Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability (the “exit price”) in an orderly transaction between market participants at the measurement date. There is a three-level hierarchy for disclosure of assets and liabilities recorded at fair value. The classification of assets and liabilities within the hierarchy is based on whether the inputs to the valuation methodology used for measurement are observable or unobservable and the significance of those inputs in the fair value measurement. Observable inputs reflect market-derived or market-based information obtained from independent sources, while unobservable inputs reflect our estimates about market data and views of market participants. The three levels for measuring fair value are based on the reliability of inputs and are as follows:
	Level 1
	Fair value measurements based on quoted prices in active markets for identical assets or liabilities that we have the ability to access. Since valuations are based on quoted prices that are readily and regularly available in an active market, valuation of these instruments does not entail a significant degree of judgment. Assets utilizing Level 1 inputs include U.S. Treasury securities, exchange-traded equity securities and certain marketable securities accounted for under fair value accounting.
	Level 2
	Fair value measurements based on quoted prices in markets that are not active or for which all significant inputs are observable, directly or indirectly. Valuations for the available-for-sale securities are provided by third party external pricing service providers. We review the methodologies used to determine the fair value, including understanding the nature and observability of the inputs used to determine the price. Additional corroboration, such as obtaining a non-binding price from a broker, may be obtained depending on the frequency of trades of the security and the level of liquidity or depth of the market. The valuation methodology that is generally used for the Level 2 assets is the income approach. Below is a summary of the significant inputs used for each class of Level 2 assets and liabilities:
	U.S. agency debentures: Fair value measurements of U.S. agency debentures are based on the characteristics specific to bonds held, such as issuer name, coupon rate, maturity date and any applicable issuer call option features. Valuations are based on market spreads relative to similar term benchmark market interest rates, generally U.S. Treasury securities.
	Agency-issued mortgage-backed securities: Agency-issued mortgage-backed securities are pools of individual conventional mortgage loans underwritten to U.S. agency standards with similar coupon rates, tenor, and other attributes such as geographic location, loan size and origination vintage. Fair value measurements of these securities are based on observable price adjustments relative to benchmark market interest rates taking into consideration estimated loan prepayment speeds.
	Agency-issued collateralized mortgage obligations: Agency-issued collateralized mortgage obligations are structured into classes or tranches with defined cash flow characteristics and are collateralized by U.S. agency-issued mortgage pass-through securities. Fair value measurements of these securities incorporate similar characteristics of mortgage pass-through securities such as coupon rate, tenor, geographic location, loan size and origination vintage, in addition to incorporating the effect of estimated prepayment speeds on the cash flow structure of the class or tranche. These measurements incorporate observable market spreads over an estimated average life after considering the inputs listed above.
	Agency-issued commercial mortgage-backed securities: Fair value measurements of these securities are based on spreads to benchmark market interest rates (usually U.S. Treasury rates or rates observable in the swaps market), prepayment speeds, loan default rate assumptions and loan loss severity assumptions on underlying loans.
	Municipal bonds and notes: Bonds issued by municipal governments generally have stated coupon rates, final maturity dates and are subject to being called ahead of the final maturity date at the option of the issuer. Fair value measurements of these securities are priced based on spreads to other municipal benchmark bonds with similar characteristics; or, relative to market rates on U.S. Treasury bonds of similar maturity.
	Interest rate derivative assets and liabilities: Fair value measurements of interest rate derivatives are priced considering the coupon rate of the fixed leg of the contract and the variable coupon on the floating leg of the contract. Valuation is based on both spot and forward rates on the swap yield curve and the credit worthiness of the contract counterparty.
	Foreign exchange forward and option contract assets and liabilities: Fair value measurements of these assets and liabilities are priced based on spot and forward foreign currency rates and option volatility assumptions.
	Equity warrant assets (public portfolio): Fair value measurements of equity warrant assets of publicly-traded portfolio companies are valued based on the Black-Scholes option pricing model. The model uses the price of publicly-traded companies (underlying stock price), stated strike prices, warrant expiration dates, the risk-free interest rate and market-observable option volatility assumptions.
	Level 3
	The fair value measurement is derived from valuation techniques that use significant assumptions not observable in the market. These unobservable assumptions reflect our own estimates of assumptions we believe market participants would use in pricing the asset. Below is a summary of the valuation techniques used for each class of Level 3 assets:
	Venture capital and private equity fund investments: Fair value measurements are based on the net asset value per share as obtained from the investee funds' management, as the funds do not have a readily determinable fair value and the funds prepare their financial statements using guidance consistent with fair value accounting. We account for differences between our measurement date and the date of the fund investment’s net asset value by using the most recent available financial information from the investee general partner, adjusted for any contributions paid, distributions received from the investment, and significant fund transactions or market events during the reporting period.
	Other venture capital investments: Fair value measurements are based on consideration of a range of factors including, but not limited to, the price at which the investment was acquired, the term and nature of the investment, local market conditions, values for comparable securities, and as it relates to the private company, the current and projected operating performance, exit strategies and financing transactions subsequent to the acquisition of the investment. The significant unobservable inputs used in the fair value measurement include the information about each portfolio company, including actual and forecasted results, cash position, recent or planned transactions and market comparable companies. Significant changes to any one of these inputs in isolation could result in a significant change in the fair value measurement, however, we generally consider all factors available through ongoing communication with the portfolio companies and venture capital fund managers to determine whether there are changes to the portfolio company or the environment that indicate a change in the fair value measurement.
	Other securities: Fair value measurements of equity securities of public companies are priced based on quoted market prices less a discount if the securities are subject to certain sales restrictions. Marketability discounts generally range from 10% to 20% depending on the duration of the sale restrictions which typically range from 3 to 6 months.
	Equity warrant assets (public portfolio): Fair value measurements of equity warrant assets of publicly-traded portfolio companies are valued based on the Black-Scholes option pricing model. The model uses the price of publicly-traded companies (underlying stock price), stated strike prices, warrant expiration dates, the risk-free interest rate and market-observable option volatility assumptions. Modeled asset values are further adjusted by applying a discount of up to 20% for certain warrants that have lockup restrictions or other features that indicate a discount to fair value is warranted. As a lock-up term nears, and other sale restrictions are lifted, discounts are adjusted downward to 0 percent once all restrictions expire or are removed.
	Equity warrant assets (private portfolio): Fair value measurements of equity warrant assets of private portfolio companies are priced based on a modified Black-Scholes option pricing model to estimate the asset value by using stated strike prices, option expiration dates, risk-free interest rates and option volatility assumptions. Option volatility assumptions used in the modified Black-Scholes model are based on public market indices whose members operate in similar industries as companies in our private company portfolio. Option expiration dates are modified to account for estimates to actual life relative to stated expiration. Overall model asset values are further adjusted for a general lack of liquidity due to the private nature of the associated underlying company. There is a direct correlation between changes in the volatility and remaining life assumptions in isolation and the fair value measurement while there is an inverse correlation between changes in the liquidity discount assumption and the fair value measurement.
	It is our policy to maximize the use of observable inputs and minimize the use of unobservable inputs when developing fair value measurements. When available, we use quoted market prices to measure fair value. If market prices are not available, fair value measurement is based upon valuation techniques that use primarily market-based or independently-sourced market parameters, including interest rate yield curves, prepayment speeds, option volatilities and currency rates. Substantially all of our financial instruments use the foregoing methodologies, and are categorized as a Level 1 or Level 2 measurement in the fair value hierarchy. However, in certain cases, when market observable inputs for our valuation techniques may not be readily available, we are required to make judgments about assumptions we believe market participants would use in estimating the fair value of the financial instrument, and based on the significance of those judgments, the measurement may be determined to be a Level 3 fair value measurement.
	The degree of management judgment involved in determining the fair value of a financial instrument is dependent upon the availability of quoted market prices or observable market parameters. For financial instruments that trade actively and have quoted market prices or observable market parameters, there is minimal subjectivity involved in measuring fair value. When observable market prices and parameters are not fully available, management judgment is necessary to estimate fair value. For inactive markets, there is little information, if any, to evaluate if individual transactions are orderly. Accordingly, we are required to estimate, based upon all available facts and circumstances, the degree to which orderly transactions are occurring and provide more weighting to price quotes that are based upon orderly transactions. In addition, changes in the market conditions may reduce the availability of quoted prices or observable data. For example, reduced liquidity in the capital markets or changes in secondary market activities could result in observable market inputs becoming unavailable. Therefore, when market data is not available, we use valuation techniques requiring more management judgment to estimate the appropriate fair value measurement. Accordingly, the degree of judgment exercised by management in determining fair value is greater for financial assets and liabilities categorized as Level 3.
	The following fair value hierarchy table presents information about our assets and liabilities that are measured at fair value on a recurring basis as of March 31, 2015:
	(Dollars in thousands)		Level 1		Level 2			Level 3		Balance at March 31, 2015
	Assets
	Available-for-sale securities:
	U.S. treasury securities		$	7,914,125	$	—		$	—	$	7,914,125
	U.S. agency debentures		—		3,313,664			—		3,313,664
	Residential mortgage-backed securities:
	Agency-issued collateralized mortgage obligations - fixed rate		—		1,778,155			—		1,778,155
	Agency-issued collateralized mortgage obligations - variable rate		—		739,203			—		739,203
	Equity securities		1,382		394			—		1,776
	Total available-for-sale securities		7,915,507		5,831,416			—		13,746,923
	Non-marketable and other securities (fair value accounting):
	Non-marketable securities:
	Venture capital and private equity fund investments		—		—			1,195,303		1,195,303
	Other venture capital investments		—		—			78,850		78,850
	Other securities		11,936		—			—		11,936
	Total non-marketable and other securities (fair value accounting)		11,936		—			1,274,153		1,286,089
	Other assets:
	Interest rate swaps		—		4,340			—		4,340
	Foreign exchange forward and option contracts		—		54,495			—		54,495
	Equity warrant assets		—		2,195			122,261		124,456
	Client interest rate derivatives		—		2,907			—		2,907
	Total assets (1)		$	7,927,443	$	5,895,353		$	1,396,414	$	15,219,210
	Liabilities
	Foreign exchange forward and option contracts		$	—	$	45,727		$	—	$	45,727
	Client interest rate derivatives		—		3,166			—		3,166
	Total liabilities		$	—	$	48,893		$	—	$	48,893
	-1	Included in Level 1 and Level 3 assets are $9 million and $1.2 billion, respectively, attributable to noncontrolling interests calculated based on the ownership percentages of the noncontrolling interests.
	The following fair value hierarchy table presents information about our assets and liabilities that are measured at fair value on a recurring basis as of December 31, 2014:
	(Dollars in thousands)		Level 1		Level 2			Level 3		Balance at December 31, 2014
	Assets
	Available-for-sale securities:
	U.S. treasury securities		$	7,302,273	$	—		$	—	$	7,302,273
	U.S. agency debentures		—		3,561,556			—		3,561,556
	Residential mortgage-backed securities:
	Agency-issued collateralized mortgage obligations - fixed rate		—		1,884,843			—		1,884,843
	Agency-issued collateralized mortgage obligations - variable rate		—		784,475			—		784,475
	Equity securities		4,290		3,218			—		7,508
	Total available-for-sale securities		7,306,563		6,234,092			—		13,540,655
Non-marketable and other securities (fair value accounting):
Non-marketable securities:
Venture capital and private equity fund investments		—		—			1,130,882		1,130,882
Other venture capital investments		—		—			71,204		71,204
Other securities		108,251		—			—		108,251
Total non-marketable and other securities (fair value accounting)		108,251		—			1,202,086		1,310,337
Other assets:
Interest rate swaps		—		4,609			—		4,609
Foreign exchange forward and option contracts		—		34,231			—		34,231
Equity warrant assets		—		1,906			114,698		116,604
Client interest rate derivatives		—		2,546			—		2,546
Total assets (1)		$	7,414,814	$	6,277,384		$	1,316,784	$	15,008,982
Liabilities
Foreign exchange forward and option contracts		$	—	$	28,363		$	—	$	28,363
Client interest rate derivatives		—		2,748			—		2,748
Total liabilities		$	—	$	31,111		$	—	$	31,111
-1	Included in Level 1 and Level 3 assets are $100 million and $1.1 billion, respectively, attributable to noncontrolling interests calculated based on the ownership percentages of the noncontrolling interests.
The following table presents additional information about Level 3 assets measured at fair value on a recurring basis for the three months ended March 31, 2015 and 2014, respectively:
(Dollars in thousands)		Beginning		Total Realized and Unrealized Gains Included in Income			Purchases		Sales			Issuances		Distributions and Other Settlements			Transfers Out of Level 3			Ending
		Balance																		Balance
Three months ended March 31, 2015
Non-marketable and other securities (fair value accounting):
Venture capital and private equity fund investments		$	1,130,882	$	46,854		$	58,670	$	—		$	—	$	(41,103	)	$	—		$	1,195,303
Other venture capital investments		71,204		6,450			1,370		(39		)	—		(135		)	—			78,850
Total non-marketable and other securities (fair value accounting)(1)		1,202,086		53,304			60,040		(39		)	—		(41,238		)	—			1,274,153
Other assets:
Equity warrant assets (2)		114,698		20,084			—		(14,765		)	2,083		404			(243		)	122,261
Total assets		$	1,316,784	$	73,388		$	60,040	$	(14,804	)	$	2,083	$	(40,834	)	$	(243	)	$	1,396,414
Three months ended March 31, 2014
Non-marketable and other securities (fair value accounting):
Venture capital and private equity fund investments		$	862,972	$	111,335		$	44,455	$	—		$	—	$	(41,840	)	$	—		$	976,922
Other venture capital investments		32,839		1,838			670		(3,514		)	—		(3,527		)	—			28,306
Other securities (fair value accounting)		319,249		102,694			—		(46,840		)	—		3,417			(16,033		)	362,487
Total non-marketable and other securities (fair value accounting) (1)		1,215,060		215,867			45,125		(50,354		)	—		(41,950		)	(16,033		)	1,367,715
Other assets:
Equity warrant assets (2)		99,891		24,378			—		(39,993		)	3,417		626			(677		)	87,642
Total assets		$	1,314,951	$	240,245		$	45,125	$	(90,347	)	$	3,417	$	(41,324	)	$	(16,710	)	$	1,455,357
-1	Realized and unrealized gains (losses) are recorded in the line items “gains on investment securities, net”, and “other noninterest income”, components of noninterest income.
-2	Realized and unrealized gains (losses) are recorded in the line item “gains on derivative instruments, net”, a component of noninterest income.
The following table presents the amount of unrealized gains (losses) included in earnings (which is inclusive of noncontrolling interest) attributable to Level 3 assets still held at March 31, 2015 and 2014:
		Three months ended March 31,
(Dollars in thousands)		2015		2014
Non-marketable and other securities (fair value accounting):
Venture capital and private equity fund investments		$	45,935	$	111,856
Other venture capital investments		6,379		(15		)
Other securities (fair value accounting)		—		78,968
Total non-marketable and other securities (fair value accounting) (1)		52,314		190,809
Other assets:
Equity warrant assets (2)		16,261		3,782
Total unrealized gains, net		$	68,575	$	194,591
Unrealized gains attributable to noncontrolling interests		$	49,617	$	176,085
-1	Unrealized gains (losses) are recorded in the line items “gains on investment securities, net”, and “other noninterest income”, components of noninterest income.
-2	Unrealized gains (losses) are recorded in the line item “gains on derivative instruments, net”, a component of noninterest income.
The following table presents quantitative information about the significant unobservable inputs used for certain of our Level 3 fair value measurements at March 31, 2015 and December 31, 2014. We have not included in this table our venture capital and private equity fund investments (fair value accounting) as we use net asset value per share (as obtained from the general partners of the investments) as a practical expedient to determine fair value.
(Dollars in thousands)		Fair value		Valuation Technique		Significant Unobservable Inputs	Weighted
							Average
March 31, 2015:
Other venture capital investments (fair value accounting)		$	78,850	Private company equity pricing		-1	(1	)
Equity warrant assets (public portfolio)		1,472		Modified Black-Scholes option pricing model		Volatility	46.6	%
						Risk-Free interest rate	1.8	%
						Sales restrictions discount (2)	15.2	%
Equity warrant assets (private portfolio)		120,789		Modified Black-Scholes option pricing model		Volatility	38.1	%
						Risk-Free interest rate	0.7	%
						Marketability discount (3)	18.1	%
						Remaining life assumption (4)	45	%
December 31, 2014:
Other venture capital investments (fair value accounting)		$	71,204	Private company equity pricing		-1	(1	)
Equity warrant assets (public portfolio)		1,681		Modified Black-Scholes option pricing model		Volatility	42.6	%
						Risk-Free interest rate	1.7	%
						Sales restrictions discount (2)	17.8	%
Equity warrant assets (private portfolio)		113,017		Modified Black-Scholes option pricing model		Volatility	38.3	%
						Risk-Free interest rate	0.9	%
						Marketability discount (3)	20	%
						Remaining life assumption (4)	45	%
-1	In determining the fair value of our other venture capital investment portfolio, we evaluate a variety of factors related to each underlying private portfolio company including, but not limited to, actual and forecasted results, cash position, recent or planned transactions and market comparable companies. Additionally, we have ongoing communication with the portfolio companies and venture capital fund managers, to determine whether there is a material change in fair value. These factors are specific to each portfolio company and a weighted average or range of values of the unobservable inputs is not meaningful.
-2	We adjust quoted market prices of public companies, which are subject to certain sales restrictions. Sales restriction discounts generally range from 10 percent to 20 percent depending on the duration of the sales restrictions, which typically range from 3 to 6 months.
-3	Our marketability discount is applied to all private company warrants to account for a general lack of liquidity due to the private nature of the associated underlying company. The quantitative measure used is based upon various option-pricing models. On a quarterly basis, a sensitivity analysis is performed on our marketability discount.
-4	We adjust the contractual remaining term of private company warrants based on our estimate of the actual remaining life, which we determine by utilizing historical data on cancellations and exercises. At March 31, 2015, the weighted average contractual remaining term was 2.61 years, compared to our estimated remaining life of 5.80 years. On a quarterly basis, a sensitivity analysis is performed on our remaining life assumption.
For the three months ended March 31, 2015 and 2014, we did not have any material transfers between Level 2 and Level 1. Transfers from Level 3 to Level 1 for the three months ended March 31, 2014 included $16.0 million as a result of the expiration of lockup and other restrictions on certain of our other securities. We did not have any transfers from Level 3 to Level 1 for the three months ended March 31, 2015.
All other transfers from Level 3 to Level 2 for the three months ended March 31, 2015 and 2014 were due to the transfer of equity warrant assets from our private portfolio to our public portfolio (see our Level 3 reconciliation above). All amounts reported as transfers represent the fair value as of the date of the change in circumstances that caused the transfer.
Assets and Liabilities Recorded at Fair Value on a Nonrecurring Basis
Net long-lived assets held-for-sale
The fair value of assets held-for-sale is estimated by their net realizable value, which represents the potential sales price less costs to sell. Valuation techniques utilized are significant assumptions not observable in the market, accordingly, we classify these assets as Level 3. The carrying value of $48.2 million of our net long-lived assets held-for-sale at March 31, 2015 approximates fair value. At December 31, 2014, the carrying value and fair value of our net long-lived assets held-for-sale was $44.3 million and $45.4 million, respectively.
Financial Instruments not Carried at Fair Value
FASB guidance over financial instruments requires that we disclose estimated fair values for our financial instruments not carried at fair value. Fair value estimates, methods and assumptions, set forth below for our financial instruments, are made solely to comply with these requirements.
Fair values are based on estimates or calculations at the transaction level using present value techniques in instances where quoted market prices are not available. Because broadly traded markets do not exist for many of our financial instruments, the fair value calculations attempt to incorporate the effect of current market conditions at a specific time. The aggregation of the fair value calculations presented herein does not represent, and should not be construed to represent, the underlying value of the Company.
The following describes the methods and assumptions used in estimating the fair values of financial instruments for which carrying value approximates fair value and estimated fair values of financial instruments not recorded at fair value on a recurring basis and excludes financial instruments and assets and liabilities already recorded at fair value as described above.
Financial Instruments for which Carrying Value Approximates Fair Value
Certain financial instruments that are not carried at fair value on the Consolidated Balance Sheets are carried at amounts that approximate fair value, due to their short-term nature and generally negligible credit risk. These instruments include cash and cash equivalents; FHLB and FRB stock; accrued interest receivable; short-term borrowings; short-term time deposits; and accrued interest payable. In addition, U.S. GAAP requires that the fair value of deposit liabilities with no stated maturity (i.e., demand, savings and certain money market deposits) be equal to their carrying value; recognition of the inherent funding value of these instruments is not permitted.
Estimated Fair Values of Financial Instruments Not Recorded at Fair Value on a Recurring Basis
Held-to-Maturity Securities
Held-to-maturity securities include similar investments held in our available-for-sale securities portfolio and are valued using the same methodologies. All securities included in our held-to-maturity securities portfolio are valued using Level 2 inputs. Refer to Level 2 fair value measurements above for significant inputs used in the valuation of our held-to-maturity investment securities.
Non-Marketable Securities (Cost and Equity Method Accounting)
Non-marketable securities includes other investments (equity method accounting), venture capital and private equity fund investments (cost method accounting), and other venture capital investments (cost method accounting). Other investments (equity method accounting) includes our investment in SPD-SVB, our joint venture bank in China. At this time, the carrying value of our investment in SPD-SVB is a reasonable estimate of fair value. The fair value of the remaining other investments (equity method accounting) and the fair value of venture capital and private equity fund investments (cost method accounting) and other venture capital investments (cost method accounting) is based on financial information obtained from the investee or obtained from the fund investments’ or debt fund investments’ respective general partners. For private company investments, estimated fair value is based on consideration of a range of factors including, but not limited to, the price at which the investment was acquired, the term and nature of the investment, local market conditions, values for comparable securities, current and projected operating performance, exit strategies, and financing transactions subsequent to the acquisition of the investment. For our fund investments, we utilize the net asset value per share as obtained from the general partners of the investments. We adjust the net asset value per share for differences between our measurement date and the date of the fund investment’s net asset value by using the most recently available financial information from the investee general partner, for example December 31st, for our March 31st consolidated financial statements, adjusted for any contributions paid, distributions received from the investment, and significant fund transactions or market events during the reporting period.
Loans
The fair value of fixed and variable rate loans is estimated by discounting contractual cash flows using rates that reflect current pricing for similar loans and the projected forward yield curve. This method is not based on the exit price concept of fair value required under ASC 820, Fair Value Measurements and Disclosures.
Long-Term Deposits
The fair value of long-term time deposits is estimated by discounting the cash flows using our cost of borrowings and the projected forward yield curve over their remaining contractual term.
Long-Term Debt
The fair value of long-term debt is generally based on quoted market prices, when available, or is estimated based on calculations utilizing third-party pricing services and current market spread, price indications from reputable dealers or observable market prices of the underlying instrument(s), whichever is deemed more reliable. Also included in the estimated fair value of our 6.05% Subordinated Notes are amounts related to hedge accounting associated with the notes.
Off-Balance Sheet Financial Instruments
The fair value of net available commitments to extend credit is estimated based on the average amount we would receive or pay to execute a new agreement with identical terms and pricing, while taking into account the counterparties’ credit standing.
Letters of credit are carried at their fair value, which was equivalent to the residual premium or fee at March 31, 2015 and December 31, 2014. Commitments to extend credit and letters of credit typically result in loans with a market interest rate if funded.
The following fair value hierarchy table presents the estimated fair values of our financial instruments that are not carried at fair value at March 31, 2015 and December 31, 2014:
				Estimated Fair Value
(Dollars in thousands)		Carrying Amount		Level 1			Level 2		Level 3
March 31, 2015:
Financial assets:
Cash and cash equivalents		$	1,308,003	$	1,308,003		$	—	$	—
Held-to-maturity securities		7,816,797		—			7,869,653		—
Non-marketable securities (cost and equity method accounting)		295,427		—			—		402,301
Net commercial loans		12,900,215		—			—		13,034,516
Net consumer loans		1,371,484		—			—		1,347,284
FHLB and Federal Reserve Bank stock		53,496		—			—		53,496
Accrued interest receivable		91,415		—			91,415		—
Financial liabilities:
Short-term FHLB advances		60,000		60,000			—		—
Other short-term borrowings		17,766		17,766			—		—
Non-maturity deposits (1)		33,752,797		33,752,797			—		—
Time deposits		98,778		—			98,740		—
3.50% Senior Notes		349,710		—			348,639		—
5.375% Senior Notes		348,495		—			396,799		—
6.05% Subordinated Notes (2)		49,910		—			52,963		—
7.0% Junior Subordinated Debentures		54,802		—			53,109		—
Accrued interest payable		5,038		—			5,038		—
Off-balance sheet financial assets:
Commitments to extend credit		—		—			—		30,135
December 31, 2014:
Financial assets:
Cash and cash equivalents		$	1,796,062	$	1,796,062		$	—	$	—
Held-to-maturity securities		7,421,042		—			7,415,656		—
Non-marketable securities (cost and equity method accounting)		296,648		—			—		390,570
Net commercial loans		12,947,869		—			—		13,082,487
Net consumer loans		1,271,048		—			—		1,247,336
FHLB and Federal Reserve Bank stock		53,496		—			—		53,496
Accrued interest receivable		94,180		—			94,180		—
Financial liabilities:
Other short-term borrowings		7,781		7,781			—		—
Non-maturity deposits (1)		34,215,372		34,215,372			—		—
Time deposits		128,127		—			128,107		—
5.375% Senior Notes		348,436		—			392,616		—
6.05% Subordinated Notes (2)		50,162		—			53,537		—
7.0% Junior Subordinated Debentures		54,845		—			52,990		—
Accrued interest payable		6,998		—			6,998		—
Off-balance sheet financial assets:
Commitments to extend credit		—		—			—		29,097
-1	Includes noninterest-bearing demand deposits, interest-bearing checking accounts, money market accounts and interest-bearing sweep deposits.
-2	At March 31, 2015 and December 31, 2014, included in the carrying value and estimated fair value of our 6.05% Subordinated Notes was an interest rate swap valued at $4.3 million and $4.6 million, respectively, related to hedge accounting associated with the notes.
Investments in Entities that Calculate Net Asset Value Per Share
FASB guidance over certain fund investments requires that we disclose the fair value of funds, significant investment strategies of the investees, redemption features of the investees, restrictions on the ability to sell investments, estimate of the period of time over which the underlying assets are expected to be liquidated by the investee, and unfunded commitments related to the investments.
Our investments in debt funds and venture capital and private equity fund investments generally cannot be redeemed. Alternatively, we expect distributions, if any, to be received primarily through IPOs and M&A activity of the underlying assets of the fund. Subject to applicable requirements under the Volcker Rule, we do not have any plans to sell any of these fund investments. If we decide to sell these investments in the future, the investee fund’s management must approve of the buyer before the sale of the investments can be completed. The fair values of the fund investments have been estimated using the net asset value per share of the investments, adjusted for any differences between our measurement date and the date of the fund investment’s net asset value by using the most recently available financial information from the investee general partner, for example December 31st, for our March 31st consolidated financial statements, adjusted for any contributions paid, distributions received from the investment, and significant fund transactions or market events during the reporting period.
The following table is a summary of the estimated fair values of these investments and remaining unfunded commitments for each major category of these investments as of March 31, 2015:
(Dollars in thousands)		Carrying Amount		Fair Value			Unfunded
							Commitments
Non-marketable securities (fair value accounting):
Venture capital and private equity fund investments (1)		$	1,195,303	$	1,195,303		$	557,992
Non-marketable securities (equity method accounting):
Other investments (2)		50,132		51,323			5,836
Non-marketable securities (cost method accounting):
Venture capital and private equity fund investments (3)		134,575		238,293			15,985
Total		$	1,380,010	$	1,484,919		$	579,813
-1	Venture capital and private equity fund investments within non-marketable securities (fair value accounting) include investments made by our managed funds of funds and one of our direct venture funds. These investments represent investments in venture capital and private equity funds that invest primarily in U.S. and global technology and life science & healthcare companies. Included in the fair value and unfunded commitments of fund investments under fair value accounting are $1.1 billion and $555 million, respectively, attributable to noncontrolling interests. It is estimated that we will receive distributions from the fund investments over the next 10 to 13 years, depending on the age of the funds and any potential extensions of terms of the funds.
-2	Other investments within non-marketable securities (equity method accounting) include investments in debt funds and venture capital and private equity fund investments that invest in or lend money to primarily U.S. and global technology and life science & healthcare companies. It is estimated that we will receive distributions from the fund investments over the next 10 to 13 years, depending on the age of the funds.
-3	Venture capital and private equity fund investments within non-marketable securities (cost method accounting) include investments in venture capital and private equity fund investments that invest primarily in U.S. and global technology and life science & healthcare companies. It is estimated that we will receive distributions from the fund investments over the next 10 to 13 years, depending on the age of the funds and any potential extensions of the terms of the funds.

Legal_Matters

Legal Matters	3 Months Ended
	Mar. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Legal Matters	Legal Matters
	Certain lawsuits and claims arising in the ordinary course of business have been filed or are pending against us or our affiliates. In accordance with applicable accounting guidance, we establish accruals for all lawsuits, claims and expected settlements when we believe it is probable that a loss has been incurred and the amount of the loss is reasonably estimable. When a loss contingency is not both probable and estimable, we do not establish an accrual. Any such loss estimates are inherently uncertain, based on currently available information and are subject to management’s judgment and various assumptions. Due to the inherent subjectivity of these estimates and unpredictability of outcomes of legal proceedings, any amounts accrued may not represent the ultimate resolution of such matters.
	To the extent we believe any potential loss relating to such lawsuits and claims may have a material impact on our liquidity, consolidated financial position, results of operations, and/or our business as a whole and is reasonably possible but not probable, we disclose information relating to any such potential loss, whether in excess of any established accruals or where there is no established accrual. We also disclose information relating to any material potential loss that is probable but not reasonably estimable. Where reasonably practicable, we will provide an estimate of loss or range of potential loss. No disclosures are generally made for any loss contingencies that are deemed to be remote.
	Based upon information available to us, our review of lawsuits and claims filed or pending against us to date and consultation with our outside legal counsel, we have not recognized a material accrual liability for these matters, nor do we currently expect it is reasonably possible that these matters will result in a material liability to the Company. However, the outcome of litigation and other legal and regulatory matters is inherently uncertain, and it is possible that one or more of such matters currently pending or threatened could have an unanticipated material adverse effect on our liquidity, consolidated financial position, results of operations, and/or our business as a whole, in the future.

Related_Parties

Related Parties	3 Months Ended
	Mar. 31, 2015
Related Party Transactions [Abstract]
Related Parties	Related Parties
	During the three months ended March 31, 2015, the Bank made loans to related parties, including certain companies in which certain of our directors or their affiliated venture funds are beneficial owners of ten percent or more of the equity securities of such companies. Such loans: (a) were made in the ordinary course of business; (b) were made on substantially the same terms, including interest rates and collateral, as those prevailing at the time for comparable transactions with other non-related persons; and (c) did not involve more than the normal risk of collectability or present other unfavorable features. Additionally, we also provide real estate secured loans to eligible employees through our EHOP.

Subsequent_Events

Subsequent Events	3 Months Ended
	Mar. 31, 2015
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events
	The sale of all of the outstanding capital stock of SVBIF to Temasek, a Singapore investment company was completed on April 13, 2015. The final settlement of the sale did not have a material impact on our first quarter 2015 results, or subsequent results thereof.

Basis_of_Presentation_Policies

Basis of Presentation (Policies)	3 Months Ended
	Mar. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Principles of Consolidation and Presentation	Principles of Consolidation and Presentation
	Our consolidated financial statements include the accounts of SVB Financial Group and entities in which we have a controlling financial interest. We determine whether we have a controlling financial interest in an entity by evaluating whether the entity is a voting interest entity or a VIE and whether the applicable accounting guidance requires consolidation. All significant intercompany accounts and transactions have been eliminated.
	Voting interest entities are entities that have sufficient equity and provide the equity investors voting rights that enable them to make significant decisions relating to the entity’s operations. For these types of entities, the Company’s determination of whether it has a controlling interest is based on ownership of the majority of the entities’ voting equity interest or through control of management of the entities.
	VIEs are entities that, by design, either (1) lack sufficient equity to permit the entity to finance its activities without additional subordinated financial support from other parties, or (2) have equity investors that do not have the ability to make significant decisions relating to the entity’s operations through voting rights, or do not have the obligation to absorb the expected losses, or do not have the right to receive the residual returns of the entity. We determine whether we have a controlling financial interest in a VIE by considering whether our involvement with the VIE is significant and whether we are the primary beneficiary based on the following:
	1	We have the power to direct the activities of the VIE that most significantly impact the entity’s economic performance;
	2	The aggregate indirect and direct variable interests held by the Company have the obligation to absorb losses or the right to receive benefits from the entity that could be significant to the VIE; and,
	3	Qualitative and quantitative factors regarding the nature, size, and form of our involvement with the VIE.
	Voting interest entities in which we have a controlling financial interest or VIEs in which we are the primary beneficiary are consolidated into our financial statements.
	We have not provided financial or other support during the periods presented to any VIE that we were not previously contractually required to provide. We are variable interest holders in certain partnerships for which we are not the primary beneficiary. We perform on-going reassessments on the status of the entities and whether facts or circumstances have changed in relation to previously evaluated voting interest entities and our involvement in VIEs which could cause our consolidation conclusion to change.
Reclassifications	Reclassifications
	Certain prior period amounts have been reclassified to conform to current period presentations.

Stockholders_Equity_and_EPS_Ta

Stockholders' Equity and EPS (Tables)	3 Months Ended
	Mar. 31, 2015
Equity and Earnings Per Share [Abstract]
Reclassifications out of AOCI	The following table summarizes the items reclassified out of accumulated other comprehensive income into the Consolidated Statements of Income (unaudited) for the three months ended March 31, 2015 and 2014:
					Three months ended March 31,
	(Dollars in thousands)		Income Statement Location		2015				2014
	Reclassification adjustment for gains included in net income		Gains on investment securities, net		$	(2,596	)		$	(60	)
	Related tax expense		Income tax expense		1,048				24
	Total reclassification adjustment for gains included in net income, net of tax				$	(1,548	)		$	(36	)
Reconciliation of Basic EPS to Diluted EPS	The following is a reconciliation of basic EPS to diluted EPS for the three months ended March 31, 2015 and 2014:
			Three months ended March 31,
	(Dollars and shares in thousands, except per share amounts)		2015				2014
	Numerator:
	Net income available to common stockholders (1)		$	88,516			$	90,950
	Denominator:
	Weighted average common shares outstanding-basic		51,009				45,866
	Weighted average effect of dilutive securities:
	Stock options and ESPP		445				566
	Restricted stock units		265				293
	Denominator for diluted calculation		51,719				46,725
	Earnings per common share:
	Basic (1)		$	1.74			$	1.98
	Diluted		$	1.71			$	1.95
	-1	Results for the quarter ended March 31, 2014 were restated to reflect the retrospective application of adopting new accounting guidance in 2015 related to our investments in qualified affordable housing projects (ASU 2014-01). See Note 1 of the Notes to Consolidated Financial Statements for additional information.
Common Shares Excluded from Diluted EPS Calculation as They Were Deemed to be Anti-Dilutive	The following table summarizes the weighted-average common shares excluded from the diluted EPS calculation as they were deemed to be antidilutive for the three months ended March 31, 2015 and 2014:
			Three months ended March 31,
	(Shares in thousands)		2015			2014
	Stock options		241			6
	Restricted stock units		2			1
	Total		243			7

ShareBased_Compensation_Tables

Share-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share Based Compensation and Related Benefits	For the three months ended March 31, 2015 and 2014, we recorded share-based compensation and related tax benefits as follows:
		Three months ended March 31,
	(Dollars in thousands)	2015				2014
	Share-based compensation expense	$	7,771			$	7,078
	Income tax benefit related to share-based compensation expense	(2,638		)		(2,160		)
Unrecognized Share Based Compensation Expense	As of March 31, 2015, unrecognized share-based compensation expense was as follows:
	(Dollars in thousands)	Unrecognized				Average
		Expense				Expected
						Recognition
						Period - in Years
	Stock options	$	12,436			2.39
	Restricted stock units	32,100				2.4
	Total unrecognized share-based compensation expense	$	44,536
Stock Option Information Related to Equity Incentive Plan	The table below provides stock option information related to the 2006 Equity Incentive Plan for the three months ended March 31, 2015:
		Options			Weighted				Weighted Average Remaining Contractual Life in Years	Aggregate
					Average					Intrinsic Value
					Exercise Price					of In-The-
										Money
										Options
	Outstanding at December 31, 2014	1,394,888			$	66.03
	Granted	6,718			120.46
	Exercised	(140,880	)		48.97
	Forfeited	(12,400	)		82.72
	Outstanding at March 31, 2015	1,248,326			68.08				4.06	$	73,596,215
	Vested and expected to vest at March 31, 2015	1,213,499			67.45				4.01	72,313,282
	Exercisable at March 31, 2015	554,601			51.32				2.84	41,996,945
Information for Restricted Stock Units under Equity Incentive Plan	The table below provides information for restricted stock units under the 2006 Equity Incentive Plan for the three months ended March 31, 2015:
		Shares			Weighted Average Grant Date Fair Value
	Nonvested at December 31, 2014	614,666			$	79.92
	Granted	53,219			125.99
	Vested	(4,613	)		71.69
	Forfeited	(9,994	)		80.52
	Nonvested at March 31, 2015	653,278			83.73

Cash_and_Cash_Equivalents_Tabl

Cash and Cash Equivalents (Tables)	3 Months Ended
	Mar. 31, 2015
Cash and Cash Equivalents [Abstract]
Cash and Cash Equivalents	The following table details our cash and cash equivalents at March 31, 2015 and December 31, 2014:
	(Dollars in thousands)		31-Mar-15		31-Dec-14
	Cash and due from banks (1)		$	1,066,854	$	1,694,329
	Securities purchased under agreements to resell (2)		236,027		95,611
	Other short-term investment securities		5,122		6,122
	Total cash and cash equivalents		$	1,308,003	$	1,796,062
	-1	At March 31, 2015 and December 31, 2014, $236 million and $861 million, respectively, of our cash and due from banks was deposited at the Federal Reserve Bank and was earning interest at the Federal Funds target rate, and interest-earning deposits in other financial institutions were $460 million and $440 million, respectively.
	-2	At March 31, 2015 and December 31, 2014, securities purchased under agreements to resell were collateralized by U.S. Treasury securities and U.S. agency securities with aggregate fair values of $244 million and $98 million, respectively. None of these securities received as collateral were sold or pledged as of March 31, 2015 or December 31, 2014.

Investment_Securities_Tables

Investment Securities (Tables)	3 Months Ended
	Mar. 31, 2015
Investments, Debt and Equity Securities [Abstract]
Major Components of Investment Securities Portfolio	The components of our available-for-sale investment securities portfolio at March 31, 2015 and December 31, 2014 are as follows:
			31-Mar-15
	(Dollars in thousands)		Amortized			Unrealized				Unrealized				Carrying
			Cost			Gains				Losses				Value
	Available-for-sale securities, at fair value:
	U.S. treasury securities		$	7,842,942		$	71,447			$	(264	)		$	7,914,125
	U.S. agency debentures		3,271,203			43,675				(1,214		)		3,313,664
	Residential mortgage-backed securities:
	Agency-issued collateralized mortgage obligations—fixed rate		1,769,610			15,005				(6,460		)		1,778,155
	Agency-issued collateralized mortgage obligations—variable rate		733,999			5,207				(3		)		739,203
	Equity securities		1,948			121				(293		)		1,776
	Total available-for-sale securities		$	13,619,702		$	135,455			$	(8,234	)		$	13,746,923
			31-Dec-14
	(Dollars in thousands)		Amortized			Unrealized				Unrealized				Carrying
			Cost			Gains				Losses				Value
	Available-for-sale securities, at fair value:
	U.S. treasury securities		$	7,289,135		$	17,524			$	(4,386	)		$	7,302,273
	U.S. agency debentures		3,540,055			30,478				(8,977		)		$	3,561,556
	Residential mortgage-backed securities:
	Agency-issued collateralized mortgage obligations—fixed rate		1,884,450			14,851				(14,458		)		1,884,843
	Agency-issued collateralized mortgage obligations—variable rate		779,103			5,372				—				784,475
	Equity securities		5,202			2,628				(322		)		7,508
	Total available-for-sale securities		$	13,497,945		$	70,853			$	(28,143	)		$	13,540,655
Summary of Unrealized Losses on Available for Sale Securities	The following table summarizes our unrealized losses on our available-for-sale securities portfolio into categories of less than 12 months and 12 months or longer as of March 31, 2015:
			31-Mar-15
			Less than 12 months							12 months or longer								Total
	(Dollars in thousands)		Fair Value of			Unrealized				Fair Value of				Unrealized				Fair Value of				Unrealized
			Investments			Losses				Investments				Losses				Investments				Losses
	Available-for-sale securities:
	U.S. treasury securities		$	176,467		$	(264	)		$	—			$	—			$	176,467			$	(264	)
	U.S. agency debentures		390,034			(1,214		)		—				—				390,034				(1,214		)
	Residential mortgage-backed securities:
	Agency-issued mortgage-backed securities		—			—				—				—				—				—
	Agency-issued collateralized mortgage obligations—fixed rate		244,285			(244		)		428,635				(6,216		)		672,920				(6,460		)
	Agency-issued collateralized mortgage obligations—variable rate		934			(3		)		—				—				934				(3		)
	Equity securities		1,381			(293		)		—				—				1,381				(293		)
	Total temporarily impaired securities: (1)		$	813,101		$	(2,018	)		$	428,635			$	(6,216	)		$	1,241,736			$	(8,234	)
	-1	As of March 31, 2015, we identified a total of 51 investments that were in unrealized loss positions, of which 17 investments totaling $428.6 million with unrealized losses of $6.2 million have been in an impaired position for a period of time greater than 12 months. As of March 31, 2015, we do not intend to sell any impaired fixed income investment securities prior to recovery of our adjusted cost basis, and it is more likely than not that we will not be required to sell any of our securities prior to recovery of our adjusted cost basis. Based on our analysis as of March 31, 2015, we deem all impairments to be temporary, and therefore changes in value for our temporarily impaired securities as of the same date are included in other comprehensive income. Market valuations and impairment analyses on assets in the available-for-sale securities portfolio are reviewed and monitored on a quarterly basis.
	The following table summarizes our unrealized losses on our available-for-sale securities portfolio into categories of less than 12 months and 12 months or longer as of December 31, 2014:
			31-Dec-14
			Less than 12 months							12 months or longer								Total
	(Dollars in thousands)		Fair Value of			Unrealized				Fair Value of				Unrealized				Fair Value of				Unrealized
			Investments			Losses				Investments				Losses				Investments				Losses
	Available-for-sale securities:
	U.S. treasury securities		$	2,297,895		$	(4,386	)		$	—			$	—			$	2,297,895			$	(4,386	)
	U.S. agency debentures		249,266			(489		)		507,385				(8,488		)		756,651				(8,977		)
	Residential mortgage-backed securities:
	Agency-issued mortgage-backed securities		—			—				—				—				—				—
	Agency-issued collateralized mortgage obligations—fixed rate		662,092			(3,104		)		453,801				(11,354		)		1,115,893				(14,458		)
	Equity securities		568			(322		)		—				—				568				(322		)
	Total temporarily impaired securities:		$	3,209,821		$	(8,301	)		$	961,186			$	(19,842	)		$	4,171,007			$	(28,143	)
Summary of Remaining Contractual Principal Maturities and Fully Taxable Equivalent Yields on Securities	The following table summarizes the remaining contractual principal maturities and fully taxable equivalent yields on fixed income investment securities classified as available-for-sale as of March 31, 2015. The weighted average yield is computed using the amortized cost of fixed income investment securities, which are reported at fair value. For U.S. treasury securities, the expected maturity is the actual contractual maturity of the notes. Expected remaining maturities for certain U.S. agency debentures may occur earlier than their contractual maturities because the note issuers have the right to call outstanding amounts ahead of their contractual maturity. Expected maturities for mortgage-backed securities may differ significantly from their contractual maturities because mortgage borrowers have the right to prepay outstanding loan obligations with or without penalties. Mortgage-backed securities classified as available-for-sale typically have original contractual maturities from 10 to 30 years whereas expected average lives of these securities tend to be significantly shorter and vary based upon structure and prepayments in lower rate environments.
			31-Mar-15
			Total						One Year							After One Year to							After Five Years to				After
									or Less							Five Years							Ten Years				Ten Years
	(Dollars in thousands)		Carrying			Weighted-			Carrying				Weighted-			Carrying				Weighted-			Carrying		Weighted-		Carrying		Weighted-
			Value			Average			Value				Average			Value				Average			Value		Average		Value		Average
						Yield							Yield							Yield					Yield				Yield
	U.S. treasury securities		$	7,914,125		1.11	%		$	350,203			0.25	%		$	6,925,629			1.09	%		$	638,293	1.9	%	$	—	—	%
	U.S. agency debentures		3,313,664			1.65			835,499				1.8			2,055,046				1.44			423,119		2.36		—		—
	Residential mortgage-backed securities:
	Agency-issued collateralized mortgage obligations - fixed rate		1,778,155			1.99			—				—			—				—			651,254		2.58		1,126,901		1.65
	Agency-issued collateralized mortgage obligations - variable rate		739,203			0.71			—				—			—				—			—		—		739,203		0.71
	Total		$	13,745,147		1.33			$	1,185,702			1.34			$	8,980,675			1.17			$	1,712,666	2.27		$	1,866,104	1.28
	The following table summarizes the remaining contractual principal maturities and fully taxable equivalent yields on fixed income investment securities classified as held-to-maturity as of March 31, 2015. Interest income on certain municipal bonds and notes (non-taxable investments) are presented on a fully taxable equivalent basis using the federal statutory tax rate of 35%. The weighted average yield is computed using the amortized cost of fixed income investment securities, which are reported at fair value. Expected remaining maturities for certain U.S. agency debentures may occur earlier than their contractual maturities because the note issuers have the right to call outstanding amounts ahead of their contractual maturity. Expected maturities for mortgage-backed securities may differ significantly from their contractual maturities because mortgage borrowers have the right to prepay outstanding loan obligations with or without penalties. Mortgage-backed securities classified as held-to-maturity typically have original contractual maturities from 10 to 30 years whereas expected average lives of these securities tend to be significantly shorter and vary based upon structure and prepayments in lower rate environments.
			31-Mar-15
			Total						One Year							After One Year to							After Five Years to				After
									or Less							Five Years							Ten Years				Ten Years
	(Dollars in thousands)		Amortized Cost			Weighted-			Amortized Cost				Weighted-			Amortized Cost				Weighted-			Amortized Cost		Weighted-		Amortized Cost		Weighted-
						Average							Average							Average					Average				Average
						Yield							Yield							Yield					Yield				Yield
	U.S. agency debentures		$	473,373		2.69	%		$	—			—	%		$	—			—	%		$	473,373	2.69	%	$	—	—	%
	Residential mortgage-backed securities:
	Agency-issued mortgage-backed securities		2,693,488			2.42			—				—			42,382				2.38			794,716		2.23		1,856,390		2.51
	Agency-issued collateralized mortgage obligations - fixed rate		3,553,640			1.65			—				—			—				—			—		—		3,553,640		1.65
	Agency-issued collateralized mortgage obligations - variable rate		124,195			0.65			—				—			—				—			—		—		124,195		0.65
	Agency-issued commercial mortgage-backed securities		888,823			2.16			—				—			—				—			—		—		888,823		2.16
	Municipal bonds and notes		83,278			6			3,442				5.39			33,261				5.87			40,081		6.11		6,494		6.34
	Total		$	7,816,797		2.07			$	3,442			5.39			$	75,643			3.91			$	1,308,170	2.52		$	6,429,542	1.95
Held-to-maturity Securities	The components of our held-to-maturity investment securities portfolio at March 31, 2015 and December 31, 2014 are as follows:
			31-Mar-15
	(Dollars in thousands)		Amortized			Unrealized				Unrealized				Fair Value
			Cost			Gains				Losses
	Held-to-maturity securities, at cost:
	U.S. agency debentures (1)		$	473,373		$	8,700			$	—			$	482,073
	Residential mortgage-backed securities:
	Agency-issued mortgage-backed securities		2,693,488			23,143				(501		)		2,716,130
	Agency-issued collateralized mortgage obligations—fixed rate		3,553,640			19,339				(6,328		)		3,566,651
	Agency-issued collateralized mortgage obligations—variable rate		124,195			337				(5		)		124,527
	Agency-issued commercial mortgage-backed securities		888,823			9,023				(498		)		897,348
	Municipal bonds and notes		83,278			126				(480		)		82,924
	Total held-to-maturity securities		$	7,816,797		$	60,668			$	(7,812	)		$	7,869,653
	-1	Consists of pools of Small Business Investment Company debentures issued and guaranteed by the U.S. Small Business Administration, an independent agency of the United States.
			December 31, 2014
	(Dollars in thousands)		Amortized			Unrealized				Unrealized				Fair Value
			Cost			Gains				Losses
	Held-to-maturity securities, at cost:
	U.S. agency debentures (1)		$	405,899		$	4,589			$	(38	)		$	410,450
	Residential mortgage-backed securities:
	Agency-issued mortgage-backed securities		2,799,923			5,789				(2,320		)		2,803,392
	Agency-issued collateralized mortgage obligations—fixed rate		3,185,109			4,521				(14,885		)		3,174,745
	Agency-issued collateralized mortgage obligations—variable rate		131,580			371				—				131,951
	Agency-issued commercial mortgage-backed securities		814,589			1,026				(3,800		)		811,815
	Municipal bonds and notes		83,942			18				(657		)		83,303
	Total held-to-maturity securities		$	7,421,042		$	16,314			$	(21,700	)		$	7,415,656
	-1	Consists of pools of Small Business Investment Company debentures issued and guaranteed by the U.S. Small Business Administration, an independent agency of the United States.
	The following table summarizes our unrealized losses on our held-to-maturity securities portfolio into categories of less than 12 months and 12 months or longer as of March 31, 2015:
			31-Mar-15
			Less than 12 months							12 months or longer								Total
	(Dollars in thousands)		Fair Value of			Unrealized				Fair Value of				Unrealized				Fair Value of				Unrealized
			Investments			Losses				Investments				Losses				Investments				Losses
	Held-to-maturity securities:
	Residential mortgage-backed securities:
	Agency-issued mortgage-backed securities		$	52,761		$	(501	)		$	—			$	—			$	52,761			$	(501	)
	Agency-issued collateralized mortgage obligations—fixed rate		622,767			(6,328		)		—				—				622,767				(6,328		)
	Agency-issued collateralized mortgage obligations—variable rate		8,660			(5		)		—				—				8,660				(5		)
	Agency-issued commercial mortgage-backed securities		164,668			(498		)		—				—				164,668				(498		)
	Municipal bonds and notes		48,864			(480		)		—				—				48,864				(480		)
	Total temporarily impaired securities (1):		$	897,720		$	(7,812	)		$	—			$	—			$	897,720			$	(7,812	)
	-1	As of March 31, 2015, we identified a total of 120 investments that were in unrealized loss positions, none of which have been in an impaired position for a period of time greater than 12 months. As of March 31, 2015, we do not intend to sell any impaired fixed income investment securities prior to recovery of our adjusted cost basis, and it is more likely than not that we will not be required to sell any of our securities prior to recovery of our adjusted cost basis, which is consistent with our classification of these securities. Based on our analysis as of March 31, 2015, we deem all impairments to be temporary. Market valuations and impairment analyses on assets in the held-to-maturity securities portfolio are reviewed and monitored on a quarterly basis.
	The following table summarizes our unrealized losses on our held-to-maturity securities portfolio into categories of less than 12 months and 12 months or longer as of December 31, 2014:
			31-Dec-14
			Less than 12 months							12 months or longer (1)								Total
	(Dollars in thousands)		Fair Value of			Unrealized				Fair Value of				Unrealized				Fair Value of				Unrealized
			Investments			Losses				Investments				Losses				Investments				Losses
	Held-to-maturity securities:
	U.S. agency debentures		$	48,335		$	(38	)		$	—			$	—			$	48,335			$	(38	)
	Residential mortgage-backed securities:
	Agency-issued mortgage-backed securities		999,230			(2,320		)		—				—				999,230				(2,320		)
	Agency-issued collateralized mortgage obligations—fixed rate		1,682,348			(9,705		)		783,558				(5,180		)		2,465,906				(14,885		)
	Agency-issued commercial mortgage-backed securities		629,840			(3,800		)		—				—				629,840				(3,800		)
	Municipal bonds and notes		79,141			(657		)		—				—				79,141				(657		)
	Total temporarily impaired securities:		$	3,438,894		$	(16,520	)		$	783,558			$	(5,180	)		$	4,222,452			$	(21,700	)
	-1	Represents securities in an unrealized loss position for twelve months or longer in which the amortized cost basis was re-set for those securities re-designated from AFS to HTM effective June 1, 2014.
Schedule of Nonmarketable and Other Securities	The components of our non-marketable and other investment securities portfolio at March 31, 2015 and December 31, 2014 are as follows:
	(Dollars in thousands)		31-Mar-15			31-Dec-14
	Non-marketable and other securities:
	Non-marketable securities (fair value accounting):
	Venture capital and private equity fund investments (1)		$	1,195,303		$	1,130,882
	Other venture capital investments (2)		78,850			71,204
	Other securities (fair value accounting) (3)		11,936			108,251
	Non-marketable securities (equity method accounting):
	Other investments (4)		145,942			142,674
	Non-marketable securities (cost method accounting):
	Venture capital and private equity fund investments (5)		134,575			140,551
	Other investments (6)		14,910			13,423
	Investments in qualified affordable housing projects (6)		125,357			121,155
	Total non-marketable and other securities		$	1,706,873		$	1,728,140
	-1	The following table shows the amounts of venture capital and private equity fund investments held by the following consolidated funds and our ownership percentage of each fund at March 31, 2015 and December 31, 2014 (fair value accounting):
			31-Mar-15						31-Dec-14
	(Dollars in thousands)		Amount			Ownership %			Amount				Ownership %
	SVB Strategic Investors Fund, LP		$	23,953		12.6	%		$	24,645			12.6	%
	SVB Strategic Investors Fund II, LP		89,219			8.6			97,250				8.6
	SVB Strategic Investors Fund III, LP		257,539			5.9			269,821				5.9
	SVB Strategic Investors Fund IV, LP		297,752			5			291,291				5
	Strategic Investors Fund V Funds		260,292			Various			226,111				Various
	Strategic Investors Fund VI Funds		127,721			—			89,605				—
	Strategic Investors Fund VII Funds		2,212			—			—				—
	SVB Capital Preferred Return Fund, LP		64,417			20			62,110				20
	SVB Capital—NT Growth Partners, LP		64,078			33			61,973				33
	SVB Capital Partners II, LP (i)		346			5.1			302				5.1
	Other private equity fund (ii)		7,774			58.2			7,774				58.2
	Total venture capital and private equity fund investments		$	1,195,303					$	1,130,882
	(i)	At March 31, 2015, we had a direct ownership interest of 1.3 percent and an indirect ownership interest of 3.8 percent in the fund through our ownership interest of SVB Strategic Investors Fund II, LP.
	(ii)	At March 31, 2015, we had a direct ownership interest of 41.5 percent and indirect ownership interests of 12.6 percent and 4.1 percent in the fund through our ownership interest of SVB Capital—NT Growth Partners, LP and SVB Capital Preferred Return Fund, LP, respectively.
	-2	The following table shows the amounts of other venture capital investments held by the following consolidated funds and our ownership percentage of each fund at March 31, 2015 and December 31, 2014 (fair value accounting):
			31-Mar-15						31-Dec-14
	(Dollars in thousands)		Amount			Ownership %			Amount				Ownership %
	Silicon Valley BancVentures, LP		$	3,390		10.7	%		$	3,291			10.7	%
	SVB Capital Partners II, LP (i)		27,215			5.1			20,481				5.1
	Capital Partners III, LP		41,055			—			41,055				—
	SVB Capital Shanghai Yangpu Venture Capital Fund		7,190			6.8			6,377				6.8
	Total other venture capital investments		$	78,850					$	71,204
	(i)	At March 31, 2015, we had a direct ownership interest of 1.3 percent and an indirect ownership interest of 3.8 percent in the fund through our ownership of SVB Strategic Investors Fund II, LP.
	-3	Investments classified as other securities (fair value accounting) represent direct equity investments in public companies held by our consolidated funds. At December 31, 2014, the amount primarily included total unrealized gains in one public company, FireEye, Inc. ("FireEye"). During the first quarter of 2015, our managed direct venture funds distributed the remaining 2.5 million shares of FireEye common stock to their respective investors (including the Company), resulting in $15.9 million of realized gains on investment securities ($3.3 million net of noncontrolling interests but inclusive of the Company's carried interests). As of March 31, 2015, we no longer hold any shares of FireEye common stock, either directly or through our managed direct venture funds.
	-4	The following table shows the carrying value and our ownership percentage of each investment at March 31, 2015 and December 31, 2014 (equity method accounting):
			31-Mar-15						31-Dec-14
	(Dollars in thousands)		Amount			Ownership %			Amount				Ownership %
	Gold Hill Capital 2008, LP (i)		$	22,040		15.5	%		$	21,294			15.5	%
	China Joint Venture investment		79,695			50			79,569				50
	Other investments		44,207			Various			41,811				Various
	Total other investments (equity method accounting)		$	145,942					$	142,674
	(i)	At March 31, 2015, we had a direct ownership interest of 11.5 percent in the fund and an indirect interest in the fund through our investment in Gold Hill Capital 2008, LLC of 4.0 percent.
	-5	Represents investments in 277 and 281 funds (primarily venture capital funds) at March 31, 2015 and December 31, 2014, respectively, where our ownership interest is typically less than 5% of the voting interests of each such fund and in which we do not have the ability to exercise significant influence over the partnerships operating activities and financial policies. The carrying value, and estimated fair value, of these venture capital and private equity fund investments (cost method accounting) was $135 million, and $238 million, respectively, as of March 31, 2015. The carrying value, and estimated fair value, of these venture capital and private equity fund investments (cost method accounting) was $141 million and $234 million, respectively, as of December 31, 2014.
	-6	Prior period amounts have been revised to reflect the retrospective application of new accounting guidance adopted in the first quarter of 2015 related to our investments in qualified affordable housing projects (ASU 2014-01). See Note 1 - "Basis of Presentation" of the "Notes to Interim Consolidated Financial Statements" under Part I, Item 1 in this report.
Components of Gains and Losses (Realized and Unrealized) on Investment Securities	The following table presents the components of gains and losses (realized and unrealized) on investment securities for the three months ended March 31, 2015 and 2014:
			Three months ended March 31,
	(Dollars in thousands)		2015			2014
	Gross gains on investment securities:
	Available-for-sale securities, at fair value (1)		$	2,690		$	373
	Non-marketable securities (fair value accounting):
	Venture capital and private equity fund investments		58,489			111,436
	Other venture capital investments		6,450			2,582
	Other securities (fair value accounting)		19,601			116,750
	Non-marketable securities (equity method accounting):
	Other investments		4,188			3,642
	Non-marketable securities (cost method accounting):
	Venture capital and private equity fund investments		4,833			3,303
	Other investments		358			134
	Total gross gains on investment securities		96,609			238,220
	Gross losses on investment securities:
	Available-for-sale securities, at fair value (1)		(94		)	(313		)
	Non-marketable securities (fair value accounting):
	Venture capital and private equity fund investments		(11,635		)	(101		)
	Other venture capital investments		—			(744		)
	Other securities (fair value accounting)		(994		)	(12,773		)
	Non-marketable securities (equity method accounting):
	Other investments		(588		)	(212		)
	Non-marketable securities (cost method accounting):
	Venture capital and private equity fund investments (2)		(134		)	(156		)
	Other investments		(5		)	(9		)
	Total gross losses on investment securities		(13,450		)	(14,308		)
	Gains on investment securities, net		$	83,159		$	223,912
	-1	Includes realized gains (losses) on sales of available-for-sale equity securities that are recognized in the income statement. Unrealized gains (losses) on available-for-sale fixed income and equity securities are recognized in other comprehensive income. The cost basis of available-for-sale securities sold is determined on a specific identification basis.
	-2	For the three months ended March 31, 2015 and 2014, includes OTTI losses of $0.1 million from the declines in value for 9 of the 277 investments and $0.1 million from the declines in value for 7 of the 282 investments, respectively. We concluded that any declines in value for the remaining investments were temporary, and as such, no OTTI was required to be recognized.

Loans_and_Allowance_for_Loan_L1

Loans and Allowance for Loan Losses (Tables)	3 Months Ended
	Mar. 31, 2015
Receivables [Abstract]
Loans and Allowance for Loan Losses	The composition of loans, net of unearned income of $107 million and $104 million at March 31, 2015 and December 31, 2014, respectively, is presented in the following table:
	(Dollars in thousands)		31-Mar-15		31-Dec-14
	Commercial loans:
	Software and internet		$	4,871,574	$	4,954,676
	Hardware		1,067,386		1,131,006
	Private equity/venture capital		4,508,670		4,582,906
	Life science & healthcare		1,399,449		1,289,904
	Premium wine		186,070		187,568
	Other		289,010		234,551
	Total commercial loans		12,322,159		12,380,611
	Real estate secured loans:
	Premium wine (1)		613,114		606,753
	Consumer loans (2)		1,209,153		1,118,115
	Other		39,422		39,651
	Total real estate secured loans		1,861,689		1,764,519
	Construction loans		85,684		78,626
	Consumer loans		170,042		160,520
	Total loans, net of unearned income (3)		$	14,439,574	$	14,384,276
	-1	Included in our premium wine portfolio are gross construction loans of $108 million and $112 million at March 31, 2015 and December 31, 2014, respectively.
	-2	Consumer loans secured by real estate at March 31, 2015 and December 31, 2014 were comprised of the following:
	(Dollars in thousands)		31-Mar-15		31-Dec-14
	Loans for personal residence		$	1,001,125	$	918,629
	Loans to eligible employees		139,761		133,568
	Home equity lines of credit		68,267		65,918
	Consumer loans secured by real estate		$	1,209,153	$	1,118,115
	-3	Included within our total loan portfolio are credit card loans of $154 million and $131 million at March 31, 2015 and December 31, 2014, respectively.
Composition of Loans, Net of Unearned Income, Broken Out by Portfolio Segment and Class of Financing Receivable	The composition of loans, net of unearned income of $107 million and $104 million at March 31, 2015 and December 31, 2014, respectively, broken out by portfolio segment and class of financing receivable, is as follows:
	(Dollars in thousands)		March 31, 2015		December 31, 2014
	Commercial loans:
	Software and internet		$	4,871,574	$	4,954,676
	Hardware		1,067,386		1,131,006
	Private equity/venture capital		4,508,670		4,582,906
	Life science & healthcare		1,399,449		1,289,904
	Premium wine		799,184		794,321
	Other		414,116		352,828
	Total commercial loans		13,060,379		13,105,641
	Consumer loans:
	Real estate secured loans		1,209,153		1,118,115
	Other consumer loans		170,042		160,520
	Total consumer loans		1,379,195		1,278,635
	Total loans, net of unearned income		$	14,439,574	$	14,384,276
Aging of Gross Loans, Broken out by Portfolio Segment and Class of Financing Receivable	The following table summarizes the aging of our gross loans, broken out by portfolio segment and class of financing receivable as of March 31, 2015 and December 31, 2014:
	(Dollars in thousands)		30 - 59		60 - 89			Greater		Total Past			Current		Loans Past Due
			Days Past		Days Past			Than 90		Due					90 Days or
			Due		Due			Days Past							More Still
								Due							Accruing
															Interest
	March 31, 2015:
	Commercial loans:
	Software and internet		$	1,970	$	162		$	160	$	2,292		$	4,876,739	$	160
	Hardware		298		9,219			—		9,517			1,066,598		—
	Private equity/venture capital		11,462		—			—		11,462			4,536,175		—
	Life science & healthcare		3,768		—			1,689		5,457			1,405,856		1,689
	Premium wine		—		—			—		—			800,197		—
	Other		1,074		—			—		1,074			410,752		—
	Total commercial loans		18,572		9,381			1,849		29,802			13,096,317		1,849
	Consumer loans:
	Real estate secured loans		415		—			1,250		1,665			1,206,762		1,250
	Other consumer loans		410		625			—		1,035			168,782		—
	Total consumer loans		825		625			1,250		2,700			1,375,544		1,250
	Total gross loans excluding impaired loans		19,397		10,006			3,099		32,502			14,471,861		3,099
	Impaired loans		313		5,855			21,920		28,088			14,294		—
	Total gross loans		$	19,710	$	15,861		$	25,019	$	60,590		$	14,486,155	$	3,099
	December 31, 2014:
	Commercial loans:
	Software and internet		$	10,989	$	1,627		$	52	$	12,668		$	4,950,291	$	52
	Hardware		13,424		126			—		13,550			1,124,423		—
	Private equity/venture capital		40,773		—			—		40,773			4,580,526		—
	Life science & healthcare		738		786			—		1,524			1,298,728		—
	Premium wine		—		—			—		—			795,345		—
	Other		178		3			—		181			354,939		—
	Total commercial loans		66,102		2,542			52		68,696			13,104,252		52
	Consumer loans:
	Real estate secured loans		1,592		341			1,250		3,183			1,114,286		1,250
	Other consumer loans		—		—			—		—			160,212		—
	Total consumer loans		1,592		341			1,250		3,183			1,274,498		1,250
	Total gross loans excluding impaired loans		67,694		2,883			1,302		71,879			14,378,750		1,302
	Impaired loans		598		1,293			22,320		24,211			13,926		—
	Total gross loans		$	68,292	$	4,176		$	23,622	$	96,090		$	14,392,676	$	1,302
Impaired Loans and Allowance for Loan Losses, Broken out by Portfolio Segment and Class of Financing Receivable	The following table summarizes our impaired loans as they relate to our allowance for loan losses, broken out by portfolio segment and class of financing receivable as of March 31, 2015 and December 31, 2014:
	(Dollars in thousands)		Impaired loans for		Impaired loans for			Total carrying value of impaired loans		Total unpaid
			which there is a		which there is no					principal of impaired loans
			related allowance		related allowance
			for loan losses		for loan losses
	March 31, 2015:
	Commercial loans:
	Software and internet		$	34,716	$	—		$	34,716	$	35,027
	Hardware		510		—			510		525
	Private equity/venture capital		—		—			—		—
	Life science & healthcare		250		—			250		2,453
	Premium wine		—		1,270			1,270		1,734
	Other		5,356		—			5,356		5,360
	Total commercial loans		40,832		1,270			42,102		45,099
	Consumer loans:
	Real estate secured loans		30		180			210		1,438
	Other consumer loans		70		—			70		254
	Total consumer loans		100		180			280		1,692
	Total		$	40,932	$	1,450		$	42,382	$	46,791
	December 31, 2014:
	Commercial loans:
	Software and internet		$	33,287	$	—		$	33,287	$	34,218
	Hardware		1,403		1,118			2,521		2,535
	Private equity/venture capital		—		—			—		—
	Life science & healthcare		475		—			475		2,453
	Premium wine		—		1,304			1,304		1,743
	Other		233		—			233		233
	Total commercial loans		35,398		2,422			37,820		41,182
	Consumer loans:
	Real estate secured loans		—		192			192		1,412
	Other consumer loans		125		—			125		305
	Total consumer loans		125		192			317		1,717
	Total		$	35,523	$	2,614		$	38,137	$	42,899
Average Impaired Loans, Broken out by Portfolio Segment and Class of Financing Receivable	The following table summarizes our average impaired loans, broken out by portfolio segment and class of financing receivable for the three months ended March 31, 2015 and 2014:
			Three months ended March 31,
	(Dollars in thousands)		2015		2014
	Average impaired loans:
	Commercial loans:
	Software and internet		$	33,725	$	14,677
	Hardware		1,643		16,020
	Life science & healthcare		400		1,022
	Premium wine		1,282		1,433
	Other		2,139		1,777
	Total commercial loans		39,189		34,929
	Consumer loans:
	Real estate secured loans		195		237
	Other consumer loans		88		489
	Total consumer loans		283		726
	Total average impaired loans		$	39,472	$	35,655
Activity in Allowance for Loan Losses Broken out by Portfolio Segment	The following tables summarize the activity relating to our allowance for loan losses for the three months ended March 31, 2015 and 2014, broken out by portfolio segment:
	Three months ended March 31, 2015 (dollars in thousands)		Beginning Balance December 31, 2014		Charge-offs			Recoveries		Provision for			Ending Balance March 31, 2015
										(Reduction of) Loan Losses
	Commercial loans:
	Software and internet		$	80,981	$	(1,403	)	$	447	$	2,067		$	82,092
	Hardware		25,860		(3,210		)	928		(2,320		)	21,258
	Private equity/venture capital		27,997		—			—		2,840			30,837
	Life science & healthcare		15,208		(225		)	34		306			15,323
	Premium wine		4,473		—			—		30			4,503
	Other		3,253		(649		)	10		3,537			6,151
	Total commercial loans		157,772		(5,487		)	1,419		6,460			160,164
	Consumer loans		7,587		—			132		(8		)	7,711
	Total allowance for loan losses		$	165,359	$	(5,487	)	$	1,551	$	6,452		$	167,875
	Three months ended March 31, 2014 (dollars in thousands)		Beginning Balance December 31, 2013		Charge-offs			Recoveries		Provision for			Ending Balance March 31, 2014
										(Reduction of) Loan Losses
	Commercial loans:
	Software and internet		$	64,084	$	(8,010	)	$	114	$	(947	)	$	55,241
	Hardware		36,553		(12,175		)	775		83			25,236
	Private equity/venture capital		16,385		—			—		1,291			17,676
	Life science & healthcare		11,926		(681		)	98		131			11,474
	Premium wine		3,914		—			219		(396		)	3,737
	Other		3,680		(284		)	—		645			4,041
	Total commercial loans		136,542		(21,150		)	1,206		807			117,405
	Consumer loans		6,344		—			106		(313		)	6,137
	Total allowance for loan losses		$	142,886	$	(21,150	)	$	1,312	$	494		$	123,542
Allowance for Loan Losses Individually and Collectively Evaluated for Impairment	The following table summarizes the allowance for loan losses individually and collectively evaluated for impairment as of March 31, 2015 and December 31, 2014, broken out by portfolio segment:
			31-Mar-15										31-Dec-14
			Individually Evaluated for					Collectively Evaluated for					Individually Evaluated for				Collectively Evaluated for
			Impairment					Impairment					Impairment				Impairment
	(Dollars in thousands)		Allowance for loan losses		Recorded investment in loans			Allowance for loan losses		Recorded investment in loans			Allowance for loan losses		Recorded investment in loans		Allowance for loan losses		Recorded investment in loans
	Commercial loans:
	Software and internet		$	20,942	$	34,716		$	61,150	$	4,836,858		$	13,695	$	33,287	$	67,286	$	4,921,389
	Hardware		12		510			21,246		1,066,876			1,133		2,521		24,727		1,128,485
	Private equity/venture capital		—		—			30,837		4,508,670			—		—		27,997		4,582,906
	Life science & healthcare		63		250			15,260		1,399,199			121		475		15,087		1,289,429
	Premium wine		—		1,270			4,503		797,914			—		1,304		4,473		793,017
	Other		2,705		5,356			3,446		408,760			71		233		3,182		352,595
	Total commercial loans		23,722		42,102			136,442		13,018,277			15,020		37,820		142,752		13,067,821
	Consumer loans		100		280			7,611		1,378,915			31		317		7,556		1,278,318
	Total		$	23,822	$	42,382		$	144,053	$	14,397,192		$	15,051	$	38,137	$	150,308	$	14,346,139
Credit Quality Indicators, Broken out by Portfolio Segment and Class of Financing Receivables	The following table summarizes the credit quality indicators, broken out by portfolio segment and class of financing receivables as of March 31, 2015 and December 31, 2014:
	(Dollars in thousands)		Pass		Performing			Impaired		Total
					(Criticized)
	March 31, 2015:
	Commercial loans:
	Software and internet		$	4,483,199	$	395,832		$	34,716	$	4,913,747
	Hardware		874,295		201,820			510		1,076,625
	Private equity/venture capital		4,543,600		4,037			—		4,547,637
	Life science & healthcare		1,282,275		129,038			250		1,411,563
	Premium wine		780,710		19,487			1,270		801,467
	Other		404,481		7,345			5,356		417,182
	Total commercial loans		12,368,560		757,559			42,102		13,168,221
	Consumer loans:
	Real estate secured loans		1,199,907		8,520			210		1,208,637
	Other consumer loans		165,914		3,903			70		169,887
	Total consumer loans		1,365,821		12,423			280		1,378,524
	Total gross loans		$	13,734,381	$	769,982		$	42,382	$	14,546,745
	December 31, 2014:
	Commercial loans:
	Software and internet		$	4,611,253	$	351,706		$	33,287	$	4,996,246
	Hardware		945,998		191,975			2,521		1,140,494
	Private equity/venture capital		4,615,231		6,068			—		4,621,299
	Life science & healthcare		1,165,266		134,986			475		1,300,727
	Premium wine		774,962		20,383			1,304		796,649
	Other		346,153		8,967			233		355,353
	Total commercial loans		12,458,863		714,085			37,820		13,210,768
	Consumer loans:
	Real estate secured loans		1,112,396		5,073			192		1,117,661
	Other consumer loans		158,162		2,050			125		160,337
	Total consumer loans		1,270,558		7,123			317		1,277,998
	Total gross loans		$	13,729,421	$	721,208		$	38,137	$	14,488,766
Summary of Loans Modified in Troubled Debt Restructurings ("TDRs") by Portfolio Segment and Class of Financing Receivables	The following table summarizes our loans modified in TDRs, broken out by portfolio segment and class of financing receivables at March 31, 2015 and December 31, 2014:
	(Dollars in thousands)		31-Mar-15		31-Dec-14
	Loans modified in TDRs:
	Commercial loans:
	Software and internet		$	2,707	$	3,784
	Hardware		4,510		1,118
	Premium wine		1,830		1,891
	Other		191		233
	Total commercial loans		9,238		7,026
	Consumer loans:
	Other consumer loans		1,350		125
	Total consumer loans		1,350		125
	Total		$	10,588	$	7,151
Recorded Investment in Loans Modified in TDRs	The following table summarizes the recorded investment in loans modified in TDRs, broken out by portfolio segment and class of financing receivable, for modifications made during the three months ended March 31, 2015 and 2014:
			Three months ended March 31,
	(Dollars in thousands)		2015		2014
	Loans modified in TDRs during the period:
	Commercial loans:
	Software and internet		$	—	$	9,737
	Hardware		4,000		—
	Premium wine		—		650
	Other		—		1,746
	Total commercial loans		4,000		12,133
	Consumer loans:
	Real estate secured loans		1,280		—
	Total consumer loans		1,280		—
	Total loans modified in TDRs during the period (1)		$	5,280	$	12,133
	-1	There were no partial charge-offs on loans classified as TDRs during the three months ended March 31, 2015 or March 31, 2014.
Recorded Investment in Loans Modified in TDRs within Previous 12 months Subsequently Defaulted	The following table summarizes the recorded investment in loans modified in TDRs within the previous 12 months that subsequently defaulted during the three months ended March 31, 2015. There were no TDRs modified, which defaulted during the three months ended March 31, 2014.
			Three months ended March 31,
	(Dollars in thousands)		2015
	TDRs modified within the previous 12 months that defaulted during the period:
	Consumer loans:
	Real estate secured loans		$	30
	Total TDRs modified within the previous 12 months that defaulted in the period		$	30

Disposal_Assets_HeldforSale_Ta

Disposal - Assets Held-for-Sale (Tables)	3 Months Ended
	Mar. 31, 2015
Discontinued Operations and Disposal Groups [Abstract]
Schedule of Disposal Groups, Including Discontinued Operations, Income Statement, Balance Sheet and Additional Disclosures	The following table presents the composition of SVBIF assets held-for-sale included in accrued interest receivable and other assets at March 31, 2015 and December 31, 2014:
	(Dollars in thousands)		31-Mar-15		31-Dec-14
	Assets:
	Cash and due from banks		$	2,897	$	3,054
	Securities purchased under agreement to resell and other short-term investments		6,419		11,898
	Net loans		33,276		26,800
	Premises and equipment, net		24		24
	Accrued interest receivable and other assets		10,307		7,163
	Total assets of SVBIF held-for-sale (1)		$	52,923	$	48,939
	Liabilities:
	Other liabilities		4,723		4,686
	Total liabilities of SVBIF held-for-sale (1)		$	4,723	$	4,686
	-1	Net assets of $48.2 million and $44.3 million are included in our Global Commercial Bank operating segment as reported in Note 11—”Segment Reporting” of the “Notes to Interim Consolidated Financial Statements” under Part I, Item 1 of this report.

ShortTerm_Borrowings_and_LongT1

Short-Term Borrowings and Long-Term Debt (Tables)	3 Months Ended
	Mar. 31, 2015
Debt Disclosure [Abstract]
Outstanding Short Term Borrowings and Long Term Debt	The following table represents outstanding short-term borrowings and long-term debt at March 31, 2015 and December 31, 2014:
						Carrying Value
	(Dollars in thousands)		Maturity	Principal value at March 31, 2015		March 31,		December 31,
						2015		2014
	Short-term borrowings:
	Short-term FHLB advances		1-Apr-15	$	60,000	$	60,000	$	—
	Other short-term borrowings		-1	17,766		17,766		7,781
	Total short-term borrowings					$	77,766	$	7,781
	Long-term debt:
	3.50% Senior Notes		29-Jan-25	$	350,000	$	349,710	$	—
	5.375% Senior Notes		15-Sep-20	350,000		348,495		348,436
	6.05% Subordinated Notes (2)		June 1, 2017	45,964		49,910		50,162
	7.0% Junior Subordinated Debentures		October 15, 2033	50,000		54,802		54,845
	Total long-term debt					$	802,917	$	453,443
	-1	Represents cash collateral received from certain counterparties in relation to market value exposures of derivative contracts in our favor, which includes an interest rate swap agreement related to our 6.05% Subordinated Notes.
	-2	At March 31, 2015 and December 31, 2014, included in the carrying value of our 6.05% Subordinated Notes was an interest rate swap valued at $4.3 million and $4.6 million, respectively, related to hedge accounting associated with the notes.

Derivative_Financial_Instrumen1

Derivative Financial Instruments (Tables)	3 Months Ended
	Mar. 31, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Total Notional or Contractual Amounts, Fair Value, Collateral and Net Exposure of Derivative Financial Instruments	The total notional or contractual amounts, fair value, collateral and net exposure of our derivative financial instruments at March 31, 2015 and December 31, 2014 were as follows:
					31-Mar-15																31-Dec-14
	(Dollars in thousands)		Balance Sheet		Notional or				Fair Value				Collateral				Net				Notional or				Fair Value			Collateral		Net
			Location		Contractual								-1				Exposure				Contractual							-1		Exposure
					Amount												-2				Amount									-2
	Derivatives designated as hedging instruments:
	Interest rate risks:
	Interest rate swaps		Other assets		$	45,964			$	4,340			$	2,970			$	1,370			$	45,964			$	4,609		$	2,970	$	1,639
	Derivatives not designated as hedging instruments:
	Currency exchange risks:
	Foreign exchange forwards		Other assets		179,467				8,688				5,138				3,550				200,957				5,050			2,441		2,609
	Foreign exchange forwards		Other liabilities		3,916				(677		)		—				(677		)		6,226				(489		)	—		(489		)
	Net exposure								8,011				5,138				2,873								4,561			2,441		2,120
	Other derivative instruments:
	Equity warrant assets		Other assets		198,864				124,456				—				124,456				197,878				116,604			—		116,604
	Other derivatives:
	Client foreign exchange forwards		Other assets		772,019				45,284				9,658				35,626				801,487				28,954			2,370		26,584
	Client foreign exchange forwards		Other liabilities		694,943				(44,527		)		—				(44,527		)		774,355				(27,647		)	—		(27,647		)
	Client foreign currency options		Other assets		51,483				523				—				523				34,926				227			—		227
	Client foreign currency options		Other liabilities		51,483				(523		)		—				(523		)		34,926				(227		)	—		(227		)
	Client interest rate derivatives		Other assets		377,530				2,907				—				2,907				387,410				2,546			—		2,546
	Client interest rate derivatives		Other liabilities		377,530				(3,166		)		—				(3,166		)		387,410				(2,748		)	—		(2,748		)
	Net exposure								498				9,658				(9,160		)						1,105			2,370		(1,265		)
	Net								$	137,305			$	17,766			$	119,539							$	126,879		$	7,781	$	119,098
	-1	Cash collateral received from our counterparties in relation to market value exposures of derivative contracts in our favor is recorded as a component of “short-term borrowings” on our consolidated balance sheets.
	-2	Net exposure for contracts in a gain position reflects the replacement cost in the event of nonperformance by all such counterparties. The credit ratings of our institutional counterparties as of March 31, 2015 remain at investment grade or higher and there were no material changes in their credit ratings during the three months ended March 31, 2015.
Summary of Derivative Activity and Related Impact on Consolidated Statements of Income	A summary of our derivative activity and the related impact on our consolidated statements of income for the three months ended March 31, 2015 and 2014 is as follows:
					Three months ended March 31,
	(Dollars in thousands)		Statement of income location		2015				2014
	Derivatives designated as hedging instruments:
	Interest rate risks:
	Net cash benefit associated with interest rate swaps		Interest expense—borrowings		$	638			$	639
	Changes in fair value of interest rate swaps		Net gains on derivative instruments		(3		)		(12		)
	Net gains associated with interest rate risk derivatives				$	635			$	627
	Derivatives not designated as hedging instruments:
	Currency exchange risks:
	(Losses) gains on revaluations of foreign currency instruments		Other noninterest income		$	(20,159	)		$	978
	Gains (losses) on internal foreign exchange forward contracts, net		Net gains on derivative instruments		20,018				(1,029		)
	Net losses associated with currency risk				$	(141	)		$	(51	)
	Other derivative instruments:
	Net gains on equity warrant assets		Net gains on derivative instruments		$	20,278			$	25,373
	(Losses) gains on client foreign exchange forward contracts, net		Net gains on derivative instruments		$	(507	)		$	302
	Net losses on other derivatives (1)		Net gains on derivative instruments		$	(57	)		$	(467	)
	-1	Primarily represents the change in fair value of loan conversion options.
Offsetting Assets	The following table summarizes our assets subject to enforceable master netting arrangements as of March 31, 2015 and December 31, 2014:
															Gross Amounts Not Offset in the Statement of Financial Position But Subject to Master Netting Arrangements
	(Dollars in thousands)		Gross Amounts of Recognized Assets				Gross Amounts offset in the Statement of Financial Position				Net Amounts of Assets Presented in the Statement of Financial Position				Financial Instruments				Cash Collateral Received				Net Amount
	31-Mar-15
	Derivative Assets:
	Interest rate swaps		$	4,340			$	—			$	4,340			$	(1,370	)		$	(2,970	)		$	—
	Foreign exchange forwards		53,972				—				53,972				(24,627		)		(14,796		)		14,549
	Foreign currency options		806				(283		)		523				(253		)		—				270
	Client interest rate derivatives		2,907				—				2,907				(2,907		)		—				—
	Total derivative assets:		62,025				(283		)		61,742				(29,157		)		(17,766		)		14,819
	Reverse repurchase, securities borrowing, and similar arrangements		236,027				—				236,027				(236,027		)		—				—
	Total		$	298,052			$	(283	)		$	297,769			$	(265,184	)		$	(17,766	)		$	14,819
	31-Dec-14
	Derivative Assets:
	Interest rate swaps		$	4,609			$	—			$	4,609			$	(1,639	)		$	(2,970	)		$	—
	Foreign exchange forwards		34,004				—				34,004				(17,843		)		(4,811		)		11,350
	Foreign currency options		501				(274		)		227				(144		)		—				83
	Client interest rate derivatives		2,546				—				2,546				(2,546		)		—				—
	Total derivative assets:		41,660				(274		)		41,386				(22,172		)		(7,781		)		11,433
	Reverse repurchase, securities borrowing, and similar arrangements		95,611				—				95,611				(95,611		)		—				—
	Total		$	137,271			$	(274	)		$	136,997			$	(117,783	)		$	(7,781	)		$	11,433
Offsetting Liabilities	The following table summarizes our liabilities subject to enforceable master netting arrangements as of March 31, 2015 and December 31, 2014:
															Gross Amounts Not Offset in the Statement of Financial Position But Subject to Master Netting Arrangements
	(Dollars in thousands)		Gross Amounts of Recognized Liabilities				Gross Amounts offset in the Statement of Financial Position				Net Amounts of Liabilities Presented in the Statement of Financial Position				Financial Instruments				Cash Collateral Pledged				Net Amount
	31-Mar-15
	Derivative Liabilities:
	Foreign exchange forwards		$	45,204			$	—			$	45,204			$	(8,467	)		$	—			$	36,737
	Foreign currency options		806				(283		)		523				(270		)		—				253
	Client interest rate derivatives		3,166				—				3,166				(3,166		)		—				—
	Total derivative liabilities:		49,176				(283		)		48,893				(11,903		)		—				36,990
	Repurchase, securities lending, and similar arrangements		—				—				—				—				—				—
	Total		$	49,176			$	(283	)		$	48,893			$	(11,903	)		$	—			$	36,990
	31-Dec-14
	Derivative Liabilities:
	Foreign exchange forwards		$	28,136			$	—			$	28,136			$	(16,808	)		$	—			$	11,328
	Foreign currency options		501				(274		)		227				(83		)		—				144
	Client interest rate derivatives		2,748				—				2,748				(2,748		)		—				—
	Total derivative liabilities:		31,385				(274		)		31,111				(19,639		)		—				11,472
	Repurchase, securities lending, and similar arrangements		—				—				—				—				—				—
	Total		$	31,385			$	(274	)		$	31,111			$	(19,639	)		$	—			$	11,472

Other_Noninterest_Loss_Income_1

Other Noninterest (Loss) Income and Other Noninterest Expense (Tables)	3 Months Ended
	Mar. 31, 2015
Other Income and Expenses [Abstract]
Summary of Other Noninterest Income	A summary of other noninterest (loss) income for the three months ended March 31, 2015 and 2014 is as follows:
			Three months ended March 31,
	(Dollars in thousands)		2015			2014
	Fund management fees		$	3,722		$	2,755
	Service-based fee income		2,150			2,027
	(Losses) gains on revaluation of foreign currency instruments (1)		(20,159		)	978
	Other (2)		5,207			5,440
	Total other noninterest (loss) income		$	(9,080	)	$	11,200
	-1	Represents the revaluation of foreign currency denominated financial instruments issued and held by us, primarily loans, deposits and cash.
	-2	Includes dividends on FHLB/FRB stock, correspondent bank rebate income and other fee income.
Summary of Other Noninterest Expense	A summary of other noninterest expense for the three months ended March 31, 2015 and 2014 is as follows:
			Three months ended March 31,
	(Dollars in thousands)		2015			2014
	Client services		$	3,549		$	2,359
	Telephone		1,959			1,748
	Data processing services		1,833			2,227
	Postage and supplies		765			769
	Dues and publications		585			497
	Other		4,907			1,562
	Total other noninterest expense (1)		$	13,598		$	9,162
	-1	Prior period amounts have been revised to reflect the retrospective application of new accounting guidance adopted in the first quarter of 2015 related to our investments in qualified affordable housing projects (ASU 2014-01). See Note 1 - "Basis of Presentation" of the "Notes to Interim Consolidated Financial Statements" under Part I, Item 1 in this report.

Segment_Reporting_Tables

Segment Reporting (Tables)	3 Months Ended
	Mar. 31, 2015
Segment Reporting [Abstract]
Segment Reporting	Our segment information for the three months ended March 31, 2015 and 2014 is as follows:
	(Dollars in thousands)		Global			SVB Private			SVB Capital (1)			Other Items (2)			Total
			Commercial			Bank
			Bank (1)
	Three months ended March 31, 2015
	Net interest income		$	203,755		$	9,723		$	(24	)	$	25,436		$	238,890
	(Provision for) reduction of loan losses		(6,460		)	8			—			—			(6,452		)
	Noninterest income		64,689			397			21,141			85,791			172,018
	Noninterest expense (3)		(136,282		)	(2,747		)	(3,891		)	(53,188		)	(196,108		)
	Income before income tax expense (4)		$	125,702		$	7,381		$	17,226		$	58,039		$	208,348
	Total average loans, net of unearned income		$	12,729,630		$	1,374,189		$	—		$	(57,450	)	$	14,046,369
	Total average assets (5)		35,962,427			1,921,554			269,982			1,146,626			39,300,589
	Total average deposits		32,472,827			1,251,939			—			133,013			33,857,779
	Three months ended March 31, 2014
	Net interest income		$	175,303		$	6,892		$	14		$	14,119		$	196,328
	(Provision for) reduction of loan losses		(807		)	313			—			—			(494		)
	Noninterest income		58,635			274			37,672			213,644			310,225
	Noninterest expense (3)		(120,706		)	(2,495		)	(2,635		)	(44,572		)	(170,408		)
	Income before income tax expense (4)		$	112,425		$	4,984		$	35,051		$	183,191		$	335,651
	Total average loans, net of unearned income		$	9,677,957		$	1,049,901		$	—		$	39,826		$	10,767,684
	Total average assets (5)		25,504,407			967,873			340,990			954,363			27,767,633
	Total average deposits		22,877,819			745,083			—			53,546			23,676,448
	-1	Global Commercial Bank’s and SVB Capital’s components of net interest income, noninterest income, noninterest expense and total average assets are shown net of noncontrolling interests for all periods presented. Noncontrolling interest is included within "Other Items".
	-2	The "Other Items" column reflects the adjustments necessary to reconcile the results of the operating segments to the consolidated financial statements prepared in conformity with GAAP. Noninterest income is primarily attributable to noncontrolling interests and gains on equity warrant assets. Noninterest expense primarily consists of expenses associated with corporate support functions such as finance, human resources, marketing, legal and other expenses. Additionally, average assets primarily consist of cash and cash equivalents and loans from our Community Development Finance practice as part of our responsibilities under the Community Reinvestment Act.
	-3	The Global Commercial Bank segment includes direct depreciation and amortization of $5.1 million and $4.9 million for the three months ended March 31, 2015 and 2014, respectively.
	-4	The internal reporting model used by management to assess segment performance does not calculate income tax expense by segment. Our effective tax rate is a reasonable approximation of the segment rates.
	-5	Total average assets equal the greater of total average assets or the sum of total liabilities and total stockholders’ equity for each segment.

OffBalance_Sheet_Arrangements_1

Off-Balance Sheet Arrangements, Guarantees and Other Commitments (Tables)	3 Months Ended
	Mar. 31, 2015
Disclosure Off Balance Sheet Arrangements Guarantees And Other Commitments Additional Information [Abstract]
Summary Information Related to Commitments to Extend Credit (Excluding Letters of Credit)	The following table summarizes information related to our commitments to extend credit at March 31, 2015 and December 31, 2014:
	(Dollars in thousands)		March 31,		December 31,
			2015		2014
	Loan commitments available for funding: (1)
	Fixed interest rate commitments		$	1,611,025	$	1,591,408
	Variable interest rate commitments		12,618,196		11,860,039
	Total loan commitments available for funding		14,229,221		13,451,447
	Commercial and standby letters of credit (2)		1,256,293		1,254,338
	Total unfunded credit commitments		$	15,485,514	$	14,705,785
	Commitments unavailable for funding (3)		$	1,920,937	$	1,868,489
	Maximum lending limits for accounts receivable factoring arrangements (4)		1,120,763		1,044,548
	Reserve for unfunded credit commitments (5)		38,628		36,419
	-1	Represents commitments which are available for funding, due to clients meeting all collateral, compliance and financial covenants required under loan commitment agreements.
	-2	See below for additional information on our commercial and standby letters of credit.
	-3	Represents commitments which are currently unavailable for funding, due to clients failing to meet all collateral, compliance and financial covenants under loan commitment agreements.
	-4	We extend credit under accounts receivable factoring arrangements when our clients’ sales invoices are deemed creditworthy under existing underwriting practices.
	-5	Our reserve for unfunded credit commitments includes an allowance for both our unfunded loan commitments and our letters of credit.
Summary of Commercial and Standby Letters of Credit	The table below summarizes our commercial and standby letters of credit at March 31, 2015. The maximum potential amount of future payments represents the amount that could be remitted under letters of credit if there were a total default by the guaranteed parties, without consideration of possible recoveries under recourse provisions or from the collateral held or pledged.
	(Dollars in thousands)		Expires In One		Expires After		Total Amount		Maximum Amount
			Year or Less		One Year		Outstanding		of Future Payments
	Financial standby letters of credit		$	1,137,234	$	57,997	$	1,195,231	$	1,195,231
	Performance standby letters of credit		45,105		6,550		51,655		51,655
	Commercial letters of credit		9,407		—		9,407		9,407
	Total		$	1,191,746	$	64,547	$	1,256,293	$	1,256,293
Total Capital Commitments, Unfunded Capital Commitments, and Ownership in Each Fund	The following table details our total capital commitments, unfunded capital commitments, and our ownership percentage in each fund at March 31, 2015:
	Our Ownership in Venture Capital and Private Equity Funds		SVBFG Capital Commitments		SVBFG Unfunded		SVBFG Ownership
	(Dollars in thousands)				Commitments		of each Fund (4)
	Silicon Valley BancVentures, LP		$	6,000	$	270	10.7	%
	SVB Capital Partners II, LP (1)		1,200		162		5.1
	Capital Partners III, LP		—		—		—
	SVB Capital Shanghai Yangpu Venture Capital Fund		935		—		6.8
	SVB Strategic Investors Fund, LP		15,300		688		12.6
	SVB Strategic Investors Fund II, LP		15,000		1,050		8.6
	SVB Strategic Investors Fund III, LP		15,000		1,275		5.9
	SVB Strategic Investors Fund IV, LP		12,239		2,325		5
	Strategic Investors Fund V Funds		515		178		Various
	Strategic Investors Fund VI Funds		—		—		—
	Strategic Investors Fund VII Funds		—		—		—
	SVB Capital Preferred Return Fund, LP		12,688		—		20
	SVB Capital—NT Growth Partners, LP		24,670		1,340		33
	Other private equity fund (2)		9,338		—		58.2
	Partners for Growth, LP		25,000		9,750		50
	Debt funds (equity method accounting)		63,134		4,950		Various
	Other fund investments (3)		301,172		19,268		Various
	Total		$	502,191	$	41,256
	-1	Our ownership includes direct ownership of 1.3 percent and indirect ownership interest of 3.8 percent through our investment in SVB Strategic Investors Fund II, LP.
	-2	Our ownership includes direct ownership of 41.5 percent and indirect ownership interests of 12.6 percent and 4.1 percent in the fund through our ownership interest of SVB Capital - NT Growth Partners, LP and SVB Capital Preferred Return Fund, LP, respectively.
	-3	Represents commitments to 283 funds (primarily venture capital funds) where our ownership interest is generally less than 5 percent of the voting interests of each such fund.
	-4	We are subject to the Volcker Rule, which restricts or limits us from sponsoring or having ownership interests in “covered” funds including venture capital and private equity funds. See “Business - Supervision and Regulation” under Item 1 of Part I of our 2014 Form 10-K.
Remaining Unfunded Commitments to Venture Capital or Private Equity Funds by Consolidated Managed Funds	The following table details the amounts of remaining unfunded commitments to venture capital and private equity funds by our consolidated managed funds of funds (including our interest and the noncontrolling interests) at March 31, 2015:
	Limited Partnership		Unfunded
	(Dollars in thousands)		Commitments
	SVB Strategic Investors Fund, LP		$	2,250
	SVB Strategic Investors Fund II, LP		5,021
	SVB Strategic Investors Fund III, LP		11,237
	SVB Strategic Investors Fund IV, LP		32,730
	Strategic Investors Fund V Funds		123,888
	Strategic Investors Fund VI Funds		219,750
	Strategic Investors Fund VII Funds		153,919
	SVB Capital Preferred Return Fund, LP		4,448
	SVB Capital—NT Growth Partners, LP		4,672
	Other private equity fund		77
	Total		$	557,992

Fair_Value_of_Financial_Instru1

Fair Value of Financial Instruments (Tables)	3 Months Ended
	Mar. 31, 2015
Fair Value Disclosures [Abstract]
Fair Value Hierarchy Tables Present Information about Assets and Liabilities Measured at Fair Value on a Recurring Basis	The following fair value hierarchy table presents information about our assets and liabilities that are measured at fair value on a recurring basis as of March 31, 2015:
	(Dollars in thousands)		Level 1		Level 2			Level 3		Balance at March 31, 2015
	Assets
	Available-for-sale securities:
	U.S. treasury securities		$	7,914,125	$	—		$	—	$	7,914,125
	U.S. agency debentures		—		3,313,664			—		3,313,664
	Residential mortgage-backed securities:
	Agency-issued collateralized mortgage obligations - fixed rate		—		1,778,155			—		1,778,155
	Agency-issued collateralized mortgage obligations - variable rate		—		739,203			—		739,203
	Equity securities		1,382		394			—		1,776
	Total available-for-sale securities		7,915,507		5,831,416			—		13,746,923
	Non-marketable and other securities (fair value accounting):
	Non-marketable securities:
	Venture capital and private equity fund investments		—		—			1,195,303		1,195,303
	Other venture capital investments		—		—			78,850		78,850
	Other securities		11,936		—			—		11,936
	Total non-marketable and other securities (fair value accounting)		11,936		—			1,274,153		1,286,089
	Other assets:
	Interest rate swaps		—		4,340			—		4,340
	Foreign exchange forward and option contracts		—		54,495			—		54,495
	Equity warrant assets		—		2,195			122,261		124,456
	Client interest rate derivatives		—		2,907			—		2,907
	Total assets (1)		$	7,927,443	$	5,895,353		$	1,396,414	$	15,219,210
	Liabilities
	Foreign exchange forward and option contracts		$	—	$	45,727		$	—	$	45,727
	Client interest rate derivatives		—		3,166			—		3,166
	Total liabilities		$	—	$	48,893		$	—	$	48,893
	-1	Included in Level 1 and Level 3 assets are $9 million and $1.2 billion, respectively, attributable to noncontrolling interests calculated based on the ownership percentages of the noncontrolling interests.
	The following fair value hierarchy table presents information about our assets and liabilities that are measured at fair value on a recurring basis as of December 31, 2014:
	(Dollars in thousands)		Level 1		Level 2			Level 3		Balance at December 31, 2014
	Assets
	Available-for-sale securities:
	U.S. treasury securities		$	7,302,273	$	—		$	—	$	7,302,273
	U.S. agency debentures		—		3,561,556			—		3,561,556
	Residential mortgage-backed securities:
	Agency-issued collateralized mortgage obligations - fixed rate		—		1,884,843			—		1,884,843
	Agency-issued collateralized mortgage obligations - variable rate		—		784,475			—		784,475
	Equity securities		4,290		3,218			—		7,508
	Total available-for-sale securities		7,306,563		6,234,092			—		13,540,655
	Non-marketable and other securities (fair value accounting):
	Non-marketable securities:
	Venture capital and private equity fund investments		—		—			1,130,882		1,130,882
	Other venture capital investments		—		—			71,204		71,204
	Other securities		108,251		—			—		108,251
	Total non-marketable and other securities (fair value accounting)		108,251		—			1,202,086		1,310,337
	Other assets:
	Interest rate swaps		—		4,609			—		4,609
	Foreign exchange forward and option contracts		—		34,231			—		34,231
	Equity warrant assets		—		1,906			114,698		116,604
	Client interest rate derivatives		—		2,546			—		2,546
	Total assets (1)		$	7,414,814	$	6,277,384		$	1,316,784	$	15,008,982
	Liabilities
	Foreign exchange forward and option contracts		$	—	$	28,363		$	—	$	28,363
	Client interest rate derivatives		—		2,748			—		2,748
	Total liabilities		$	—	$	31,111		$	—	$	31,111
	-1	Included in Level 1 and Level 3 assets are $100 million and $1.1 billion, respectively, attributable to noncontrolling interests calculated based on the ownership percentages of the noncontrolling interests.
Additional Information about Level 3 Assets Measured at Fair Value on a Recurring Basis	The following table presents additional information about Level 3 assets measured at fair value on a recurring basis for the three months ended March 31, 2015 and 2014, respectively:
	(Dollars in thousands)		Beginning		Total Realized and Unrealized Gains Included in Income			Purchases		Sales			Issuances		Distributions and Other Settlements			Transfers Out of Level 3			Ending
			Balance																		Balance
	Three months ended March 31, 2015
	Non-marketable and other securities (fair value accounting):
	Venture capital and private equity fund investments		$	1,130,882	$	46,854		$	58,670	$	—		$	—	$	(41,103	)	$	—		$	1,195,303
	Other venture capital investments		71,204		6,450			1,370		(39		)	—		(135		)	—			78,850
	Total non-marketable and other securities (fair value accounting)(1)		1,202,086		53,304			60,040		(39		)	—		(41,238		)	—			1,274,153
	Other assets:
	Equity warrant assets (2)		114,698		20,084			—		(14,765		)	2,083		404			(243		)	122,261
	Total assets		$	1,316,784	$	73,388		$	60,040	$	(14,804	)	$	2,083	$	(40,834	)	$	(243	)	$	1,396,414
	Three months ended March 31, 2014
	Non-marketable and other securities (fair value accounting):
	Venture capital and private equity fund investments		$	862,972	$	111,335		$	44,455	$	—		$	—	$	(41,840	)	$	—		$	976,922
	Other venture capital investments		32,839		1,838			670		(3,514		)	—		(3,527		)	—			28,306
	Other securities (fair value accounting)		319,249		102,694			—		(46,840		)	—		3,417			(16,033		)	362,487
	Total non-marketable and other securities (fair value accounting) (1)		1,215,060		215,867			45,125		(50,354		)	—		(41,950		)	(16,033		)	1,367,715
	Other assets:
	Equity warrant assets (2)		99,891		24,378			—		(39,993		)	3,417		626			(677		)	87,642
	Total assets		$	1,314,951	$	240,245		$	45,125	$	(90,347	)	$	3,417	$	(41,324	)	$	(16,710	)	$	1,455,357
	-1	Realized and unrealized gains (losses) are recorded in the line items “gains on investment securities, net”, and “other noninterest income”, components of noninterest income.
	-2	Realized and unrealized gains (losses) are recorded in the line item “gains on derivative instruments, net”, a component of noninterest income.
Unrealized Gains Included in Earnings Attributable to Level 3 Assets Held	The following table presents the amount of unrealized gains (losses) included in earnings (which is inclusive of noncontrolling interest) attributable to Level 3 assets still held at March 31, 2015 and 2014:
			Three months ended March 31,
	(Dollars in thousands)		2015		2014
	Non-marketable and other securities (fair value accounting):
	Venture capital and private equity fund investments		$	45,935	$	111,856
	Other venture capital investments		6,379		(15		)
	Other securities (fair value accounting)		—		78,968
	Total non-marketable and other securities (fair value accounting) (1)		52,314		190,809
	Other assets:
	Equity warrant assets (2)		16,261		3,782
	Total unrealized gains, net		$	68,575	$	194,591
	Unrealized gains attributable to noncontrolling interests		$	49,617	$	176,085
	-1	Unrealized gains (losses) are recorded in the line items “gains on investment securities, net”, and “other noninterest income”, components of noninterest income.
	-2	Unrealized gains (losses) are recorded in the line item “gains on derivative instruments, net”, a component of noninterest income.
Quantitative Information About Significant Unobservable Inputs	The following table presents quantitative information about the significant unobservable inputs used for certain of our Level 3 fair value measurements at March 31, 2015 and December 31, 2014. We have not included in this table our venture capital and private equity fund investments (fair value accounting) as we use net asset value per share (as obtained from the general partners of the investments) as a practical expedient to determine fair value.
	(Dollars in thousands)		Fair value		Valuation Technique		Significant Unobservable Inputs	Weighted
								Average
	March 31, 2015:
	Other venture capital investments (fair value accounting)		$	78,850	Private company equity pricing		-1	(1	)
	Equity warrant assets (public portfolio)		1,472		Modified Black-Scholes option pricing model		Volatility	46.6	%
							Risk-Free interest rate	1.8	%
							Sales restrictions discount (2)	15.2	%
	Equity warrant assets (private portfolio)		120,789		Modified Black-Scholes option pricing model		Volatility	38.1	%
							Risk-Free interest rate	0.7	%
							Marketability discount (3)	18.1	%
							Remaining life assumption (4)	45	%
	December 31, 2014:
	Other venture capital investments (fair value accounting)		$	71,204	Private company equity pricing		-1	(1	)
	Equity warrant assets (public portfolio)		1,681		Modified Black-Scholes option pricing model		Volatility	42.6	%
							Risk-Free interest rate	1.7	%
							Sales restrictions discount (2)	17.8	%
	Equity warrant assets (private portfolio)		113,017		Modified Black-Scholes option pricing model		Volatility	38.3	%
							Risk-Free interest rate	0.9	%
							Marketability discount (3)	20	%
							Remaining life assumption (4)	45	%
	-1	In determining the fair value of our other venture capital investment portfolio, we evaluate a variety of factors related to each underlying private portfolio company including, but not limited to, actual and forecasted results, cash position, recent or planned transactions and market comparable companies. Additionally, we have ongoing communication with the portfolio companies and venture capital fund managers, to determine whether there is a material change in fair value. These factors are specific to each portfolio company and a weighted average or range of values of the unobservable inputs is not meaningful.
	-2	We adjust quoted market prices of public companies, which are subject to certain sales restrictions. Sales restriction discounts generally range from 10 percent to 20 percent depending on the duration of the sales restrictions, which typically range from 3 to 6 months.
	-3	Our marketability discount is applied to all private company warrants to account for a general lack of liquidity due to the private nature of the associated underlying company. The quantitative measure used is based upon various option-pricing models. On a quarterly basis, a sensitivity analysis is performed on our marketability discount.
	-4	We adjust the contractual remaining term of private company warrants based on our estimate of the actual remaining life, which we determine by utilizing historical data on cancellations and exercises. At March 31, 2015, the weighted average contractual remaining term was 2.61 years, compared to our estimated remaining life of 5.80 years. On a quarterly basis, a sensitivity analysis is performed on our remaining life assumption.
Summary of Estimated Fair Values of Financial Instruments Not Carried at Fair Value	Letters of credit are carried at their fair value, which was equivalent to the residual premium or fee at March 31, 2015 and December 31, 2014. Commitments to extend credit and letters of credit typically result in loans with a market interest rate if funded.
	The following fair value hierarchy table presents the estimated fair values of our financial instruments that are not carried at fair value at March 31, 2015 and December 31, 2014:
					Estimated Fair Value
	(Dollars in thousands)		Carrying Amount		Level 1			Level 2		Level 3
	March 31, 2015:
	Financial assets:
	Cash and cash equivalents		$	1,308,003	$	1,308,003		$	—	$	—
	Held-to-maturity securities		7,816,797		—			7,869,653		—
	Non-marketable securities (cost and equity method accounting)		295,427		—			—		402,301
	Net commercial loans		12,900,215		—			—		13,034,516
	Net consumer loans		1,371,484		—			—		1,347,284
	FHLB and Federal Reserve Bank stock		53,496		—			—		53,496
	Accrued interest receivable		91,415		—			91,415		—
	Financial liabilities:
	Short-term FHLB advances		60,000		60,000			—		—
	Other short-term borrowings		17,766		17,766			—		—
	Non-maturity deposits (1)		33,752,797		33,752,797			—		—
	Time deposits		98,778		—			98,740		—
	3.50% Senior Notes		349,710		—			348,639		—
	5.375% Senior Notes		348,495		—			396,799		—
	6.05% Subordinated Notes (2)		49,910		—			52,963		—
	7.0% Junior Subordinated Debentures		54,802		—			53,109		—
	Accrued interest payable		5,038		—			5,038		—
	Off-balance sheet financial assets:
	Commitments to extend credit		—		—			—		30,135
	December 31, 2014:
	Financial assets:
	Cash and cash equivalents		$	1,796,062	$	1,796,062		$	—	$	—
	Held-to-maturity securities		7,421,042		—			7,415,656		—
	Non-marketable securities (cost and equity method accounting)		296,648		—			—		390,570
	Net commercial loans		12,947,869		—			—		13,082,487
	Net consumer loans		1,271,048		—			—		1,247,336
	FHLB and Federal Reserve Bank stock		53,496		—			—		53,496
	Accrued interest receivable		94,180		—			94,180		—
	Financial liabilities:
	Other short-term borrowings		7,781		7,781			—		—
	Non-maturity deposits (1)		34,215,372		34,215,372			—		—
	Time deposits		128,127		—			128,107		—
	5.375% Senior Notes		348,436		—			392,616		—
	6.05% Subordinated Notes (2)		50,162		—			53,537		—
	7.0% Junior Subordinated Debentures		54,845		—			52,990		—
	Accrued interest payable		6,998		—			6,998		—
	Off-balance sheet financial assets:
	Commitments to extend credit		—		—			—		29,097
	-1	Includes noninterest-bearing demand deposits, interest-bearing checking accounts, money market accounts and interest-bearing sweep deposits.
	-2	At March 31, 2015 and December 31, 2014, included in the carrying value and estimated fair value of our 6.05% Subordinated Notes was an interest rate swap valued at $4.3 million and $4.6 million, respectively, related to hedge accounting associated with the notes.
Summary of Estimated Fair Values of Investments and Remaining Unfunded Commitments for Each Major Category of Investments	The following table is a summary of the estimated fair values of these investments and remaining unfunded commitments for each major category of these investments as of March 31, 2015:
	(Dollars in thousands)		Carrying Amount		Fair Value			Unfunded
								Commitments
	Non-marketable securities (fair value accounting):
	Venture capital and private equity fund investments (1)		$	1,195,303	$	1,195,303		$	557,992
	Non-marketable securities (equity method accounting):
	Other investments (2)		50,132		51,323			5,836
	Non-marketable securities (cost method accounting):
	Venture capital and private equity fund investments (3)		134,575		238,293			15,985
	Total		$	1,380,010	$	1,484,919		$	579,813
	-1	Venture capital and private equity fund investments within non-marketable securities (fair value accounting) include investments made by our managed funds of funds and one of our direct venture funds. These investments represent investments in venture capital and private equity funds that invest primarily in U.S. and global technology and life science & healthcare companies. Included in the fair value and unfunded commitments of fund investments under fair value accounting are $1.1 billion and $555 million, respectively, attributable to noncontrolling interests. It is estimated that we will receive distributions from the fund investments over the next 10 to 13 years, depending on the age of the funds and any potential extensions of terms of the funds.
	-2	Other investments within non-marketable securities (equity method accounting) include investments in debt funds and venture capital and private equity fund investments that invest in or lend money to primarily U.S. and global technology and life science & healthcare companies. It is estimated that we will receive distributions from the fund investments over the next 10 to 13 years, depending on the age of the funds.
	-3	Venture capital and private equity fund investments within non-marketable securities (cost method accounting) include investments in venture capital and private equity fund investments that invest primarily in U.S. and global technology and life science & healthcare companies. It is estimated that we will receive distributions from the fund investments over the next 10 to 13 years, depending on the age of the funds and any potential extensions of the terms of the funds.

Basis_of_Presentation_Adjustme

Basis of Presentation - Adjustments for New Guidance (Details) (Accounting Standards Update 2014-01, USD $)	3 Months Ended		12 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014		Dec. 31, 2014		Dec. 31, 2013
Accounting Standards Update 2014-01
Retained Earnings Adjustments [Line Items]
Cumulative effect on retained earnings upon adoption of new guidance			$4.70	[1]	$4.60	[1]
Decrease in previously reported net income	$0.40	[1]
[1]	Prior period amounts have been revised to reflect the retrospective application of new accounting guidance adopted in the first quarter of 2015 related to our investments in qualified affordable housing projects (ASU 2014-01). See Note 1 - "Basis of Presentation" of the "Notes to Interim Consolidated Financial Statements" under Part I, Item 1 in this report.

Stockholders_Equity_and_EPS_Re

Stockholders' Equity and EPS - Reclassifications out of AOCI (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Related tax expense	($63,066)	($61,296)	[1]
Net income available to common stockholders	88,516	90,950	[1],[2]
Reclassification out of Accumulated Other Comprehensive Income | Gains on investment securities, net
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Reclassification adjustment for (gains) losses included in net income	-2,596	-60
Related tax expense	1,048	24
Net income available to common stockholders	($1,548)	($36)
[1]	Prior period amounts have been revised to reflect the retrospective application of new accounting guidance adopted in the first quarter of 2015 related to our investments in qualified affordable housing projects (ASU 2014-01). See Note 1 - "Basis of Presentation" of the "Notes to Interim Consolidated Financial Statements" under Part I, Item 1 in this report.
[2]	Results for the quarter ended March 31, 2014 were restated to reflect the retrospective application of adopting new accounting guidance in 2015 related to our investments in qualified affordable housing projects (ASU 2014-01). See Note 1 of the Notes to Consolidated Financial Statements for additional information.

Stockholders_Equity_and_EPS_Re1

Stockholders' Equity and EPS - Reconciliation of Basic EPS to Diluted EPS (Detail) (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Numerator:
Net income available to common stockholders (1)	$88,516	$90,950	[1],[2]
Denominator:
Weighted average common shares outstanding-basic (in shares)	51,009	45,866
Denominator for diluted calculation (in shares)	51,719	46,725
Earnings per common share:
Basic (dollars per share)	$1.74	$1.98	[1],[2]
Diluted (dollars per share)	$1.71	$1.95
Stock options and ESPP
Denominator:
Weighted average effect of dilutive securities (in shares)	445	566
Restricted stock units
Denominator:
Weighted average effect of dilutive securities (in shares)	265	293
[1]	Results for the quarter ended March 31, 2014 were restated to reflect the retrospective application of adopting new accounting guidance in 2015 related to our investments in qualified affordable housing projects (ASU 2014-01). See Note 1 of the Notes to Consolidated Financial Statements for additional information.
[2]	Prior period amounts have been revised to reflect the retrospective application of new accounting guidance adopted in the first quarter of 2015 related to our investments in qualified affordable housing projects (ASU 2014-01). See Note 1 - "Basis of Presentation" of the "Notes to Interim Consolidated Financial Statements" under Part I, Item 1 in this report.

Stockholders_Equity_and_EPS_Co

Stockholders' Equity and EPS - Common Shares Excluded from Diluted EPS Calculation as They Were Deemed to be Anti-Dilutive (Detail)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares excluded from diluted earnings per share calculation	243	7
Stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares excluded from diluted earnings per share calculation	241	6
Restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares excluded from diluted earnings per share calculation	2	1

ShareBased_Compensation_Share_

Share-Based Compensation - Share Based Compensation and Related Benefits (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-based compensation expense	$7,771	$7,078
Income tax benefit related to share-based compensation expense	($2,638)	($2,160)

ShareBased_Compensation_Unreco

Share-Based Compensation - Unrecognized Share-Based Compensation Expense (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015
Unrecognized Share Based Compensation Expense [Line Items]
Unrecognized Expense	$44,536
Stock options
Unrecognized Share Based Compensation Expense [Line Items]
Unrecognized Expense	12,436
Average Expected Recognition Period - in Years	2 years 4 months 21 days
Restricted stock units
Unrecognized Share Based Compensation Expense [Line Items]
Unrecognized Expense	$32,100
Average Expected Recognition Period - in Years	2 years 4 months 24 days

ShareBased_Compensation_Stock_

Share-Based Compensation - Stock Option Information Related to Equity Incentive Plan (Detail) (USD $)	3 Months Ended
	Mar. 31, 2015
Options
Outstanding, beginning of period	1,394,888
Granted	6,718
Exercised	-140,880
Forfeited	-12,400
Outstanding, end of period	1,248,326
Vested and expected to vest, end of period	1,213,499
Exercisable, end of period	554,601
Weighted Average Exercise Price
Outstanding, beginning of period	$66.03
Granted	$120.46
Exercised	$48.97
Forfeited	$82.72
Outstanding, end of period	$68.08
Vested and expected to vest, end of period	$67.45
Exercisable, end of period	$51.32
Weighted Average Remaining Contractual Life in Years
Outstanding, end of period	4 years 22 days
Vested and expected to vest, end of period	4 years 4 days
Exercisable, end of period	2 years 10 months 2 days
Aggregate Intrinsic Value of In-The- Money Options
Outstanding, end of period	$73,596,215
Vested and expected to vest, end of period	72,313,282
Exercisable, end of period	$41,996,945

ShareBased_Compensation_Additi

Share-Based Compensation - Additional Information (Detail) (USD $)	3 Months Ended
In Millions, except Per Share data, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Closing stock price	$127.04
Total intrinsic value of options exercised	$10.20	$7.20

ShareBased_Compensation_Inform

Share-Based Compensation - Information for Restricted Stock Units under Equity Incentive Plan (Detail) (USD $)	3 Months Ended
	Mar. 31, 2015
Weighted Average Grant Date Fair Value
Nonvested, beginning of period	$79.92
Granted	$125.99
Vested	$71.69
Forfeited	$80.52
Nonvested, end of period	$83.73
Restricted stock units
Shares
Nonvested, beginning of period	614,666
Granted	53,219
Vested	-4,613
Forfeited	-9,994
Nonvested, end of period	653,278

Cash_and_Cash_Equivalents_Deta

Cash and Cash Equivalents (Detail) (USD $)	Mar. 31, 2015		Dec. 31, 2014		Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Cash and Cash Equivalents [Abstract]
Cash and due from banks	$1,066,854	[1]	$1,694,329	[1]
Securities purchased under agreements to resell	236,027	[2]	95,611	[2]
Other short-term investment securities	5,122		6,122
Total cash and cash equivalents	$1,308,003		$1,796,062		$3,862,464	$1,538,779
[1]	At March 31, 2015 and December 31, 2014, $236 million and $861 million, respectively, of our cash and due from banks was deposited at the Federal Reserve Bank and was earning interest at the Federal Funds target rate, and interest-earning deposits in other financial institutions were $460 million and $440 million, respectively.
[2]	At March 31, 2015 and December 31, 2014, securities purchased under agreements to resell were collateralized by U.S. Treasury securities and U.S. agency securities with aggregate fair values of $244 million and $98 million, respectively. None of these securities received as collateral were sold or pledged as of March 31, 2015 or December 31, 2014.

Cash_and_Cash_Equivalents_Addi

Cash and Cash Equivalents (Additional Information) (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Millions, unless otherwise specified
Cash and Cash Equivalents [Abstract]
Deposits at the Federal Reserve Bank earning interest at the Federal Funds target rate	$236	$861
Interest-earning deposits in other financial institutions	460	440
Fair value of securities purchased under agreements to resell	244	98
Fair value of securities received as collateral that have been resold or repledged	$0	$0

Investment_Securities_Major_Co

Investment Securities - Major Components of Investment Securities Portfolio (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Investment Holdings [Line Items]
Amortized Cost	$13,619,702	$13,497,945
Unrealized Gains	135,455	70,853
Unrealized Losses	-8,234	-28,143
Carrying Value	13,746,923	13,540,655
U.S. treasury securities
Investment Holdings [Line Items]
Amortized Cost	7,842,942	7,289,135
Unrealized Gains	71,447	17,524
Unrealized Losses	-264	-4,386
Carrying Value	7,914,125	7,302,273
U.S. agency debentures
Investment Holdings [Line Items]
Amortized Cost	3,271,203	3,540,055
Unrealized Gains	43,675	30,478
Unrealized Losses	-1,214	-8,977
Carrying Value	3,313,664	3,561,556
Residential mortgage-backed securities | Agency-issued collateralized mortgage obligations | Fixed rate
Investment Holdings [Line Items]
Amortized Cost	1,769,610	1,884,450
Unrealized Gains	15,005	14,851
Unrealized Losses	-6,460	-14,458
Carrying Value	1,778,155	1,884,843
Residential mortgage-backed securities | Agency-issued collateralized mortgage obligations | Variable rate
Investment Holdings [Line Items]
Amortized Cost	733,999	779,103
Unrealized Gains	5,207	5,372
Unrealized Losses	-3	0
Carrying Value	739,203	784,475
Equity securities
Investment Holdings [Line Items]
Amortized Cost	1,948	5,202
Unrealized Gains	121	2,628
Unrealized Losses	-293	-322
Carrying Value	$1,776	$7,508

Investment_Securities_Summary_

Investment Securities - Summary of Unrealized Losses on Available for Sale Securities (Detail) (USD $)	Mar. 31, 2015		Dec. 31, 2014
In Thousands, unless otherwise specified	Investment
Investments, Unrealized Loss Position [Line Items]
Less than 12 months - Fair Value of Investments	$813,101	[1]	$3,209,821
Less than 12 months - Unrealized Losses	-2,018	[1]	-8,301
12 months or longer - Unrealized Losses	428,635	[1]	961,186
12 months or longer - Unrealized Losses	-6,216	[1]	-19,842
Fair Value of Investments	1,241,736	[1]	4,171,007
Unrealized Losses	-8,234	[1]	-28,143
Number of investments in unrealized loss position	51
Number of investments with unrealized losses greater than 12 months	17
U.S. treasury securities
Investments, Unrealized Loss Position [Line Items]
Less than 12 months - Fair Value of Investments	176,467		2,297,895
Less than 12 months - Unrealized Losses	-264		-4,386
12 months or longer - Unrealized Losses	0		0
12 months or longer - Unrealized Losses	0		0
Fair Value of Investments	176,467		2,297,895
Unrealized Losses	-264		-4,386
U.S. agency debentures
Investments, Unrealized Loss Position [Line Items]
Less than 12 months - Fair Value of Investments	390,034		249,266
Less than 12 months - Unrealized Losses	-1,214		-489
12 months or longer - Unrealized Losses	0		507,385
12 months or longer - Unrealized Losses	0		-8,488
Fair Value of Investments	390,034		756,651
Unrealized Losses	-1,214		-8,977
Residential mortgage-backed securities | Agency-issued mortgage-backed securities
Investments, Unrealized Loss Position [Line Items]
Less than 12 months - Fair Value of Investments	0		0
Less than 12 months - Unrealized Losses	0		0
12 months or longer - Unrealized Losses	0		0
12 months or longer - Unrealized Losses	0		0
Fair Value of Investments	0		0
Unrealized Losses	0		0
Residential mortgage-backed securities | Agency-issued collateralized mortgage obligations | Fixed rate
Investments, Unrealized Loss Position [Line Items]
Less than 12 months - Fair Value of Investments	244,285		662,092
Less than 12 months - Unrealized Losses	-244		-3,104
12 months or longer - Unrealized Losses	428,635		453,801
12 months or longer - Unrealized Losses	-6,216		-11,354
Fair Value of Investments	672,920		1,115,893
Unrealized Losses	-6,460		-14,458
Residential mortgage-backed securities | Agency-issued collateralized mortgage obligations | Variable rate
Investments, Unrealized Loss Position [Line Items]
Less than 12 months - Fair Value of Investments	934
Less than 12 months - Unrealized Losses	-3
12 months or longer - Unrealized Losses	0
12 months or longer - Unrealized Losses	0
Fair Value of Investments	934
Unrealized Losses	-3
Equity securities
Investments, Unrealized Loss Position [Line Items]
Less than 12 months - Fair Value of Investments	1,381		568
Less than 12 months - Unrealized Losses	-293		-322
12 months or longer - Unrealized Losses	0		0
12 months or longer - Unrealized Losses	0		0
Fair Value of Investments	1,381		568
Unrealized Losses	($293)		($322)
[1]	As of March 31, 2015, we identified a total of 51 investments that were in unrealized loss positions, of which 17 investments totaling $428.6 million with unrealized losses of $6.2 million have been in an impaired position for a period of time greater than 12 months. As of March 31, 2015, we do not intend to sell any impaired fixed income investment securities prior to recovery of our adjusted cost basis, and it is more likely than not that we will not be required to sell any of our securities prior to recovery of our adjusted cost basis. Based on our analysis as of March 31, 2015, we deem all impairments to be temporary, and therefore changes in value for our temporarily impaired securities as of the same date are included in other comprehensive income. Market valuations and impairment analyses on assets in the available-for-sale securities portfolio are reviewed and monitored on a quarterly basis.

Investment_Securities_Summary_1

Investment Securities - Summary of Remaining Contractual Principal Maturities and Fully Taxable Equivalent Yields on Debt Securities Classified as Available for Sale (Detail) (Available-for-sale Securities, USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015
Investments Classified by Contractual Maturity Date [Line Items]
Available-for-sale Securities, Debt Securities	13,745,147
Weighted- Average Yield	1.33%
One Year or Less - Carrying Value	1,185,702
One Year or Less - Weighted- Average Yield	1.34%
After One Year to Five Years - Carrying Value	8,980,675
After One Year to Five Years - Weighted- Average Yield	1.17%
After Five Years to Ten Years - Carrying Value	1,712,666
After Five Years to Ten Years - Weighted- Average Yield	2.27%
After Ten Years - Carrying Value	1,866,104
After Ten Years - Weighted- Average Yield	1.28%
Lower Limit
Investments Classified by Contractual Maturity Date [Line Items]
Mortgage-backed securities contractual maturities (in years)	10 years
Upper Limit
Investments Classified by Contractual Maturity Date [Line Items]
Mortgage-backed securities contractual maturities (in years)	30 years
U.S. treasury securities
Investments Classified by Contractual Maturity Date [Line Items]
Available-for-sale Securities, Debt Securities	7,914,125
Weighted- Average Yield	1.11%
One Year or Less - Carrying Value	350,203
One Year or Less - Weighted- Average Yield	0.25%
After One Year to Five Years - Carrying Value	6,925,629
After One Year to Five Years - Weighted- Average Yield	1.09%
After Five Years to Ten Years - Carrying Value	638,293
After Five Years to Ten Years - Weighted- Average Yield	1.90%
After Ten Years - Carrying Value	0
After Ten Years - Weighted- Average Yield	0.00%
U.S. agency debentures
Investments Classified by Contractual Maturity Date [Line Items]
Available-for-sale Securities, Debt Securities	3,313,664
Weighted- Average Yield	1.65%
One Year or Less - Carrying Value	835,499
One Year or Less - Weighted- Average Yield	1.80%
After One Year to Five Years - Carrying Value	2,055,046
After One Year to Five Years - Weighted- Average Yield	1.44%
After Five Years to Ten Years - Carrying Value	423,119
After Five Years to Ten Years - Weighted- Average Yield	2.36%
After Ten Years - Carrying Value	0
After Ten Years - Weighted- Average Yield	0.00%
Residential mortgage-backed securities | Agency-issued collateralized mortgage obligations | Fixed rate
Investments Classified by Contractual Maturity Date [Line Items]
Available-for-sale Securities, Debt Securities	1,778,155
Weighted- Average Yield	1.99%
One Year or Less - Carrying Value	0
One Year or Less - Weighted- Average Yield	0.00%
After One Year to Five Years - Carrying Value	0
After One Year to Five Years - Weighted- Average Yield	0.00%
After Five Years to Ten Years - Carrying Value	651,254
After Five Years to Ten Years - Weighted- Average Yield	2.58%
After Ten Years - Carrying Value	1,126,901
After Ten Years - Weighted- Average Yield	1.65%
Residential mortgage-backed securities | Agency-issued collateralized mortgage obligations | Variable rate
Investments Classified by Contractual Maturity Date [Line Items]
Available-for-sale Securities, Debt Securities	739,203
Weighted- Average Yield	0.71%
One Year or Less - Carrying Value	0
One Year or Less - Weighted- Average Yield	0.00%
After One Year to Five Years - Carrying Value	0
After One Year to Five Years - Weighted- Average Yield	0.00%
After Five Years to Ten Years - Carrying Value	0
After Five Years to Ten Years - Weighted- Average Yield	0.00%
After Ten Years - Carrying Value	739,203
After Ten Years - Weighted- Average Yield	0.71%

Investment_Securities_Summary_2

Investment Securities - Summary of Unrealized Losses on Held to Maturity Securities (Details) (USD $)	Mar. 31, 2015		Dec. 31, 2014
In Thousands, unless otherwise specified	Investment
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	$7,816,797		$7,421,042
Unrealized Gains	60,668		16,314
Unrealized Losses	-7,812		-21,700
Fair Value	7,869,653		7,415,656
Held-to-maturity Securities, Continuous Unrealized Loss Position, Accumulated Loss [Abstract]
Fair Value of Investments, Less than 12 months	897,720		3,438,894
Unrealized Losses, Less than 12 months	-7,812		-16,520
Fair Value of Investments, 12 months or longer	0	[1]	783,558	[2]
Unrealized Losses, 12 months or longer	0	[1]	-5,180	[2]
Fair Value of Investments	897,720		4,222,452
Unrealized Losses	-7,812		-21,700
Number of held-to-maturity investments with unrealized loss	120
Number of held-to-maturity investments in continuous loss more than 12 months	0
U.S. agency debentures
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	473,373	[3]	405,899	[3]
Unrealized Gains	8,700	[3]	4,589	[3]
Unrealized Losses	0	[3]	-38	[3]
Fair Value	482,073	[3]	410,450	[3]
Held-to-maturity Securities, Continuous Unrealized Loss Position, Accumulated Loss [Abstract]
Fair Value of Investments, Less than 12 months			48,335
Unrealized Losses, Less than 12 months			-38
Fair Value of Investments, 12 months or longer			0
Unrealized Losses, 12 months or longer			0
Fair Value of Investments			48,335
Unrealized Losses			-38
Agency-issued mortgage-backed securities
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	2,693,488		2,799,923
Unrealized Gains	23,143		5,789
Unrealized Losses	-501		-2,320
Fair Value	2,716,130		2,803,392
Held-to-maturity Securities, Continuous Unrealized Loss Position, Accumulated Loss [Abstract]
Fair Value of Investments, Less than 12 months	52,761		999,230
Unrealized Losses, Less than 12 months	-501		-2,320
Fair Value of Investments, 12 months or longer	0		0
Unrealized Losses, 12 months or longer	0		0
Fair Value of Investments	52,761		999,230
Unrealized Losses	-501		-2,320
Agency-issued commercial mortgage-backed securities
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	888,823		814,589
Unrealized Gains	9,023		1,026
Unrealized Losses	-498		-3,800
Fair Value	897,348		811,815
Held-to-maturity Securities, Continuous Unrealized Loss Position, Accumulated Loss [Abstract]
Fair Value of Investments, Less than 12 months	164,668		629,840
Unrealized Losses, Less than 12 months	-498		-3,800
Fair Value of Investments, 12 months or longer	0		0
Unrealized Losses, 12 months or longer	0		0
Fair Value of Investments	164,668		629,840
Unrealized Losses	-498		-3,800
Municipal bonds and notes
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	83,278		83,942
Unrealized Gains	126		18
Unrealized Losses	-480		-657
Fair Value	82,924		83,303
Held-to-maturity Securities, Continuous Unrealized Loss Position, Accumulated Loss [Abstract]
Fair Value of Investments, Less than 12 months	48,864		79,141
Unrealized Losses, Less than 12 months	-480		-657
Fair Value of Investments, 12 months or longer	0		0
Unrealized Losses, 12 months or longer	0		0
Fair Value of Investments	48,864		79,141
Unrealized Losses	-480		-657
Fixed rate | Agency-issued collateralized mortgage obligations | Residential mortgage-backed securities
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	3,553,640		3,185,109
Unrealized Gains	19,339		4,521
Unrealized Losses	-6,328		-14,885
Fair Value	3,566,651		3,174,745
Held-to-maturity Securities, Continuous Unrealized Loss Position, Accumulated Loss [Abstract]
Fair Value of Investments, Less than 12 months	622,767		1,682,348
Unrealized Losses, Less than 12 months	-6,328		-9,705
Fair Value of Investments, 12 months or longer	0		783,558
Unrealized Losses, 12 months or longer	0		-5,180
Fair Value of Investments	622,767		2,465,906
Unrealized Losses	-6,328		-14,885
Variable rate | Agency-issued collateralized mortgage obligations | Residential mortgage-backed securities
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	124,195		131,580
Unrealized Gains	337		371
Unrealized Losses	-5		0
Fair Value	124,527		131,951
Held-to-maturity Securities, Continuous Unrealized Loss Position, Accumulated Loss [Abstract]
Fair Value of Investments, Less than 12 months	8,660
Unrealized Losses, Less than 12 months	-5
Fair Value of Investments, 12 months or longer	0
Unrealized Losses, 12 months or longer	0
Fair Value of Investments	8,660
Unrealized Losses	($5)
[1]	As of March 31, 2015, we identified a total of 120 investments that were in unrealized loss positions, none of which have been in an impaired position for a period of time greater than 12 months. As of March 31, 2015, we do not intend to sell any impaired fixed income investment securities prior to recovery of our adjusted cost basis, and it is more likely than not that we will not be required to sell any of our securities prior to recovery of our adjusted cost basis, which is consistent with our classification of these securities. Based on our analysis as of March 31, 2015, we deem all impairments to be temporary. Market valuations and impairment analyses on assets in the held-to-maturity securities portfolio are reviewed and monitored on a quarterly basis.
[2]	Represents securities in an unrealized loss position for twelve months or longer in which the amortized cost basis was re-set for those securities re-designated from AFS to HTM effective June 1, 2014.
[3]	Consists of pools of Small Business Investment Company debentures issued and guaranteed by the U.S. Small Business Administration, an independent agency of the United States.

Investment_Securities_Summary_3

Investment Securities - Summary of Remaining Contractual Principal Maturities and Fully Taxable Equivalent Yields on Debt Securities Classified as Held to Maturity (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Schedule of Held-to-maturity Securities [Line Items]
Federal statutory tax rate	35.00%
Amortized Cost	$7,816,797	$7,421,042
Held-to-maturity securities
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	7,816,797
Weighted- Average Yield	2.07%
One Year or Less - Amortized Cost	3,442
One Year or Less - Weighted- Average Yield	5.39%
One Year to Five Years - Amortized Cost	75,643
After One Year to Five Years - Weighted- Average Yield	3.91%
After Five Years to Ten Years - Amortized Cost	1,308,170
After Five Years to Ten Years - Weighted- Average Yield	2.52%
After Ten Years - Amortized Cost	6,429,542
After Ten Years - Weighted- Average Yield	1.95%
Held-to-maturity securities | Lower Limit
Schedule of Held-to-maturity Securities [Line Items]
Mortgage-backed securities contractual maturities (in years)	10 years
Held-to-maturity securities | Upper Limit
Schedule of Held-to-maturity Securities [Line Items]
Mortgage-backed securities contractual maturities (in years)	30 years
U.S. agency debentures | Held-to-maturity securities
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	473,373
Weighted- Average Yield	2.69%
One Year or Less - Amortized Cost	0
One Year or Less - Weighted- Average Yield	0.00%
One Year to Five Years - Amortized Cost	0
After One Year to Five Years - Weighted- Average Yield	0.00%
After Five Years to Ten Years - Amortized Cost	473,373
After Five Years to Ten Years - Weighted- Average Yield	2.69%
After Ten Years - Amortized Cost	0
After Ten Years - Weighted- Average Yield	0.00%
Agency-issued mortgage-backed securities | Held-to-maturity securities
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	2,693,488
Weighted- Average Yield	2.42%
One Year or Less - Amortized Cost	0
One Year or Less - Weighted- Average Yield	0.00%
One Year to Five Years - Amortized Cost	42,382
After One Year to Five Years - Weighted- Average Yield	2.38%
After Five Years to Ten Years - Amortized Cost	794,716
After Five Years to Ten Years - Weighted- Average Yield	2.23%
After Ten Years - Amortized Cost	1,856,390
After Ten Years - Weighted- Average Yield	2.51%
Residential mortgage-backed securities | Held-to-maturity securities | Agency-issued collateralized mortgage obligations | Fixed rate
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	3,553,640
Weighted- Average Yield	1.65%
One Year or Less - Amortized Cost	0
One Year or Less - Weighted- Average Yield	0.00%
One Year to Five Years - Amortized Cost	0
After One Year to Five Years - Weighted- Average Yield	0.00%
After Five Years to Ten Years - Amortized Cost	0
After Five Years to Ten Years - Weighted- Average Yield	0.00%
After Ten Years - Amortized Cost	3,553,640
After Ten Years - Weighted- Average Yield	1.65%
Residential mortgage-backed securities | Held-to-maturity securities | Agency-issued collateralized mortgage obligations | Variable rate
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	124,195
Weighted- Average Yield	0.65%
One Year or Less - Amortized Cost	0
One Year or Less - Weighted- Average Yield	0.00%
One Year to Five Years - Amortized Cost	0
After One Year to Five Years - Weighted- Average Yield	0.00%
After Five Years to Ten Years - Amortized Cost	0
After Five Years to Ten Years - Weighted- Average Yield	0.00%
After Ten Years - Amortized Cost	124,195
After Ten Years - Weighted- Average Yield	0.65%
Agency-issued commercial mortgage-backed securities | Held-to-maturity securities
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	888,823
Weighted- Average Yield	2.16%
One Year or Less - Amortized Cost	0
One Year or Less - Weighted- Average Yield	0.00%
One Year to Five Years - Amortized Cost	0
After One Year to Five Years - Weighted- Average Yield	0.00%
After Five Years to Ten Years - Amortized Cost	0
After Five Years to Ten Years - Weighted- Average Yield	0.00%
After Ten Years - Amortized Cost	888,823
After Ten Years - Weighted- Average Yield	2.16%
Municipal bonds and notes | Held-to-maturity securities
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	83,278
Weighted- Average Yield	6.00%
One Year or Less - Amortized Cost	3,442
One Year or Less - Weighted- Average Yield	5.39%
One Year to Five Years - Amortized Cost	33,261
After One Year to Five Years - Weighted- Average Yield	5.87%
After Five Years to Ten Years - Amortized Cost	40,081
After Five Years to Ten Years - Weighted- Average Yield	6.11%
After Ten Years - Amortized Cost	$6,494
After Ten Years - Weighted- Average Yield	6.34%

Investment_Securities_Nonmarke

Investment Securities - Non-marketable and Other Securities (Detail) (USD $)	3 Months Ended		12 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015		Dec. 31, 2014		Mar. 31, 2014
					Investment
Investment Holdings [Line Items]
Total non-marketable and other securities	$1,706,873		$1,728,140	[1]
Ownership interest percentage			5.00%
Low Income Housing Tax Credit Funds [Member]
Investment Holdings [Line Items]
Nonmarketable Securities Other	125,357	[1]	121,155	[1]
Fair value accounting
Investment Holdings [Line Items]
Non-marketable securities	11,936	[2]	108,251	[2]
Fair value accounting | Other venture capital investments
Investment Holdings [Line Items]
Non-marketable securities	78,850	[3]	71,204	[3]
Fair value accounting | Venture capital and private equity fund investments
Investment Holdings [Line Items]
Non-marketable securities	1,195,303	[4]	1,130,882	[4]
Non-marketable securities	238,000		234,000
Equity method accounting | Other investments
Investment Holdings [Line Items]
Non-marketable securities	145,942	[5]	142,674	[5]
Cost method accounting | Other investments
Investment Holdings [Line Items]
Non-marketable securities	14,910	[1]	13,423	[1]
Cost method accounting | Venture capital and private equity fund investments
Investment Holdings [Line Items]
Non-marketable securities	134,575	[6]	140,551	[6]
Number of investments	277		281		282
Upper Limit
Investment Holdings [Line Items]
Ownership interest percentage	5.00%
SVB Strategic Investors Fund, LP | Fair value accounting | Venture capital and private equity fund investments
Investment Holdings [Line Items]
Non-marketable securities	23,953		24,645
Percentage of ownership	12.60%		12.60%
SVB Strategic Investors Fund II, LP | Fair value accounting | Venture capital and private equity fund investments
Investment Holdings [Line Items]
Non-marketable securities	89,219		97,250
Percentage of ownership	8.60%		8.60%
SVB Strategic Investors Fund III, LP | Fair value accounting | Venture capital and private equity fund investments
Investment Holdings [Line Items]
Non-marketable securities	257,539		269,821
Percentage of ownership	5.90%		5.90%
SVB Strategic Investors Fund IV, LP | Fair value accounting | Venture capital and private equity fund investments
Investment Holdings [Line Items]
Non-marketable securities	297,752		291,291
Percentage of ownership	5.00%		5.00%
Strategic Investors Fund V Funds | Fair value accounting | Venture capital and private equity fund investments
Investment Holdings [Line Items]
Non-marketable securities	260,292		226,111
Strategic Investors Fund VI Funds | Fair value accounting | Venture capital and private equity fund investments
Investment Holdings [Line Items]
Non-marketable securities	127,721		89,605
Percentage of ownership	0.00%		0.00%
Strategic Investors Fund VII Funds [Domain] | Fair value accounting | Venture capital and private equity fund investments
Investment Holdings [Line Items]
Non-marketable securities	2,212		0
Percentage of ownership	0.00%		0.00%
SVB Capital Preferred Return Fund, LP | Fair value accounting | Venture capital and private equity fund investments
Investment Holdings [Line Items]
Non-marketable securities	64,417		62,110
Percentage of ownership	20.00%		20.00%
SVB Capital—NT Growth Partners, LP | Venture capital and private equity fund investments | Indirect ownership interest | Other investments
Investment Holdings [Line Items]
Percentage of ownership	12.60%
SVB Capital—NT Growth Partners, LP | Fair value accounting | Venture capital and private equity fund investments
Investment Holdings [Line Items]
Non-marketable securities	64,078		61,973
Percentage of ownership	33.00%		33.00%
SVB Capital Partners II, LP | Venture capital and private equity fund investments | Direct ownership interest | Other investments
Investment Holdings [Line Items]
Percentage of ownership	1.30%
SVB Capital Partners II, LP | Venture capital and private equity fund investments | Indirect ownership interest | Other investments
Investment Holdings [Line Items]
Percentage of ownership	3.80%
SVB Capital Partners II, LP | Fair value accounting | Other venture capital investments
Investment Holdings [Line Items]
Non-marketable securities	27,215	[7]	20,481	[7]
Percentage of ownership	5.10%	[7]	5.10%	[7]
SVB Capital Partners II, LP | Fair value accounting | Venture capital and private equity fund investments
Investment Holdings [Line Items]
Non-marketable securities	346	[8]	302	[8]
Percentage of ownership	5.10%	[8]	5.10%	[8]
SVB Capital Partners II, LP | Fair value accounting | Direct ownership interest | Venture capital and private equity fund investments
Investment Holdings [Line Items]
Percentage of ownership	1.30%
SVB Capital Partners II, LP | Fair value accounting | Indirect ownership interest | Venture capital and private equity fund investments
Investment Holdings [Line Items]
Percentage of ownership	3.80%
Other private equity fund | Venture capital and private equity fund investments | Direct ownership interest | Other investments
Investment Holdings [Line Items]
Percentage of ownership	41.50%
Other private equity fund | Fair value accounting | Venture capital and private equity fund investments
Investment Holdings [Line Items]
Non-marketable securities	7,774	[9]	7,774	[9]
Percentage of ownership	58.20%	[9]	58.20%	[9]
Other private equity fund | Fair value accounting | Direct ownership interest | Venture capital and private equity fund investments
Investment Holdings [Line Items]
Percentage of ownership	41.50%
Silicon Valley BancVentures, LP | Fair value accounting | Other venture capital investments
Investment Holdings [Line Items]
Non-marketable securities	3,390		3,291
Percentage of ownership	10.70%		10.70%
Capital Partners III, LP | Fair value accounting | Other venture capital investments
Investment Holdings [Line Items]
Non-marketable securities	41,055		41,055
Percentage of ownership	0.00%		0.00%
SVB Capital Shanghai Yangpu Venture Capital Fund | Fair value accounting | Other venture capital investments
Investment Holdings [Line Items]
Non-marketable securities	7,190		6,377
Percentage of ownership	6.80%		6.80%
Gold Hill Capital 2008, LP | Equity method accounting | Other investments
Investment Holdings [Line Items]
Non-marketable securities	22,040	[10]	21,294	[10]
Percentage of ownership	15.50%	[10]	15.50%	[10]
Gold Hill Capital 2008, LP | Equity method accounting | Direct ownership interest | Other investments
Investment Holdings [Line Items]
Percentage of ownership	11.50%
Gold Hill Capital 2008, LP | Equity method accounting | Indirect ownership interest | Other investments
Investment Holdings [Line Items]
Percentage of ownership	4.00%
China Joint Venture investment | Equity method accounting | Other investments
Investment Holdings [Line Items]
Non-marketable securities	79,695		79,569
Percentage of ownership	50.00%		50.00%
Other investments | Equity method accounting | Other investments
Investment Holdings [Line Items]
Non-marketable securities	$44,207		$41,811
LP and SVB Capital Preferred Return Fund, LP | Venture capital and private equity fund investments | Indirect ownership interest | Other investments
Investment Holdings [Line Items]
Percentage of ownership	4.10%
[1]	Prior period amounts have been revised to reflect the retrospective application of new accounting guidance adopted in the first quarter of 2015 related to our investments in qualified affordable housing projects (ASU 2014-01). See Note 1 - "Basis of Presentation" of the "Notes to Interim Consolidated Financial Statements" under Part I, Item 1 in this report.
[2]	Investments classified as other securities (fair value accounting) represent direct equity investments in public companies held by our consolidated funds. At December 31, 2014, the amount primarily included total unrealized gains in one public company, FireEye, Inc. ("FireEye"). During the first quarter of 2015, our managed direct venture funds distributed the remaining 2.5 million shares of FireEye common stock to their respective investors (including the Company), resulting in $15.9 million of realized gains on investment securities ($3.3 million net of noncontrolling interests but inclusive of the Company's carried interests). As of March 31, 2015, we no longer hold any shares of FireEye common stock, either directly or through our managed direct venture funds.
[3]	The following table shows the amounts of other venture capital investments held by the following consolidated funds and our ownership percentage of each fund at March 31, 2015 and December 31, 2014 (fair value accounting): March 31, 2015 December 31, 2014(Dollars in thousands) Amount Ownership % Amount Ownership %Silicon Valley BancVentures, LP $3,390 10.7% $3,291 10.7%SVB Capital Partners II, LP (i) 27,215 5.1 20,481 5.1Capital Partners III, LP 41,055 — 41,055 —SVB Capital Shanghai Yangpu Venture Capital Fund 7,190 6.8 6,377 6.8Total other venture capital investments $78,850 $71,204 (i)At March 31, 2015, we had a direct ownership interest of 1.3 percent and an indirect ownership interest of 3.8 percent in the fund through our ownership of SVB Strategic Investors Fund II, LP.
[4]	The following table shows the amounts of venture capital and private equity fund investments held by the following consolidated funds and our ownership percentage of each fund at March 31, 2015 and December 31, 2014 (fair value accounting): March 31, 2015 December 31, 2014(Dollars in thousands) Amount Ownership % Amount Ownership %SVB Strategic Investors Fund, LP $23,953 12.6% $24,645 12.6%SVB Strategic Investors Fund II, LP 89,219 8.6 97,250 8.6SVB Strategic Investors Fund III, LP 257,539 5.9 269,821 5.9SVB Strategic Investors Fund IV, LP 297,752 5.0 291,291 5.0Strategic Investors Fund V Funds 260,292 Various 226,111 VariousStrategic Investors Fund VI Funds 127,721 — 89,605 —Strategic Investors Fund VII Funds 2,212 — — —SVB Capital Preferred Return Fund, LP 64,417 20.0 62,110 20.0SVB Capital—NT Growth Partners, LP 64,078 33.0 61,973 33.0SVB Capital Partners II, LP (i) 346 5.1 302 5.1Other private equity fund (ii) 7,774 58.2 7,774 58.2Total venture capital and private equity fund investments $1,195,303 $1,130,882 (i)At March 31, 2015, we had a direct ownership interest of 1.3 percent and an indirect ownership interest of 3.8 percent in the fund through our ownership interest of SVB Strategic Investors Fund II, LP.(ii)At March 31, 2015, we had a direct ownership interest of 41.5 percent and indirect ownership interests of 12.6 percent and 4.1 percent in the fund through our ownership interest of SVB Capital—NT Growth Partners, LP and SVB Capital Preferred Return Fund, LP, respectively.
[5]	The following table shows the carrying value and our ownership percentage of each investment at March 31, 2015 and December 31, 2014 (equity method accounting): March 31, 2015 December 31, 2014(Dollars in thousands) Amount Ownership % Amount Ownership %Gold Hill Capital 2008, LP (i) $22,040 15.5% $21,294 15.5%China Joint Venture investment 79,695 50.0 79,569 50.0Other investments 44,207 Various 41,811 VariousTotal other investments (equity method accounting) $145,942 $142,674 (i)At March 31, 2015, we had a direct ownership interest of 11.5 percent in the fund and an indirect interest in the fund through our investment in Gold Hill Capital 2008, LLC of 4.0 percent.
[6]	Represents investments in 277 and 281 funds (primarily venture capital funds) at March 31, 2015 and December 31, 2014, respectively, where our ownership interest is typically less than 5% of the voting interests of each such fund and in which we do not have the ability to exercise significant influence over the partnerships operating activities and financial policies. The carrying value, and estimated fair value, of these venture capital and private equity fund investments (cost method accounting) was $135 million, and $238 million, respectively, as of March 31, 2015. The carrying value, and estimated fair value, of these venture capital and private equity fund investments (cost method accounting) was $141 million and $234 million, respectively, as of December 31, 2014.
[7]	At March 31, 2015, we had a direct ownership interest of 1.3 percent and an indirect ownership interest of 3.8 percent in the fund through our ownership of SVB Strategic Investors Fund II, LP.
[8]	At March 31, 2015, we had a direct ownership interest of 1.3 percent and an indirect ownership interest of 3.8 percent in the fund through our ownership interest of SVB Strategic Investors Fund II, LP.
[9]	At March 31, 2015, we had a direct ownership interest of 41.5 percent and indirect ownership interests of 12.6 percent and 4.1 percent in the fund through our ownership interest of SVB Capital—NT Growth Partners, LP and SVB Capital Preferred Return Fund, LP, respectively.
[10]	At March 31, 2015, we had a direct ownership interest of 11.5 percent in the fund and an indirect interest in the fund through our investment in Gold Hill Capital 2008, LLC of 4.0 percent.

Investment_Securities_Componen

Investment Securities - Components of Gains and Losses (Realized and Unrealized) on Investment Securities (Detail) (USD $)	3 Months Ended
	Mar. 31, 2015		Mar. 31, 2014		Dec. 31, 2014
	Investment		Investment		Investment
Gain (Loss) on Investments [Line Items]
Gross gains on investment securities	$96,609,000		$238,220,000
Gross losses on investment securities	-13,450,000		-14,308,000
(Losses) gains on investment securities, net	83,159,000		223,912,000
Fair value accounting | Other securities
Gain (Loss) on Investments [Line Items]
Gross gains on investment securities	19,601,000		116,750,000
Gross losses on investment securities	-994,000		-12,773,000
Cost method accounting | Venture capital and private equity fund investments
Gain (Loss) on Investments [Line Items]
Recognized other-than-temporary impairment (OTTI) losses	100,000		100,000
Number of other-than-temporary impaired investments	9		7
Number of investments	277		282		281
Available-for-sale Securities
Gain (Loss) on Investments [Line Items]
Gross gains on investment securities	2,690,000	[1]	373,000	[1]
Gross losses on investment securities	-94,000	[1]	-313,000	[1]
Non-marketable securities | Fair value accounting | Venture capital and private equity fund investments
Gain (Loss) on Investments [Line Items]
Gross gains on investment securities	58,489,000		111,436,000
Gross losses on investment securities	-11,635,000		-101,000
Non-marketable securities | Fair value accounting | Other venture capital investments
Gain (Loss) on Investments [Line Items]
Gross gains on investment securities	6,450,000		2,582,000
Gross losses on investment securities	0		-744,000
Non-marketable securities | Equity method accounting | Other investments
Gain (Loss) on Investments [Line Items]
Gross gains on investment securities	4,188,000		3,642,000
Gross losses on investment securities	-588,000		-212,000
Non-marketable securities | Cost method accounting | Venture capital and private equity fund investments
Gain (Loss) on Investments [Line Items]
Gross gains on investment securities	4,833,000		3,303,000
Gross losses on investment securities	-134,000	[2]	-156,000	[2]
Non-marketable securities | Cost method accounting | Other investments
Gain (Loss) on Investments [Line Items]
Gross gains on investment securities	358,000		134,000
Gross losses on investment securities	($5,000)		($9,000)
[1]	Includes realized gains (losses) on sales of available-for-sale equity securities that are recognized in the income statement. Unrealized gains (losses) on available-for-sale fixed income and equity securities are recognized in other comprehensive income. The cost basis of available-for-sale securities sold is determined on a specific identification basis.
[2]	For the three months ended March 31, 2015 and 2014, includes OTTI losses of $0.1 million from the declines in value for 9 of the 277 investments and $0.1 million from the declines in value for 7 of the 282 investments, respectively. We concluded that any declines in value for the remaining investments were temporary, and as such, no OTTI was required to be recognized.

Loans_and_Allowance_for_Loan_L2

Loans and Allowance for Loan Losses - Additional Information (Detail) (USD $)	3 Months Ended
	Mar. 31, 2015		Mar. 31, 2014		Dec. 31, 2014
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Deferred Income	$107,000,000				$104,000,000
Loans modified in TDRs	10,588,000				7,151,000
Unfunded commitments available for funding	3,100,000
Loans modified in TDRs during the period	5,280,000	[1]	12,133,000	[1]
Payment Deferrals Granted
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans modified in TDRs during the period			$9,300,000
[1]	There were no partial charge-offs on loans classified as TDRs during the three months ended March 31, 2015 or March 31, 2014.

Loans_and_Allowance_for_Loan_L3

Loans and Allowance for Loan Losses - Composition of Loans, Net of Unearned income (Detail) (USD $)	Mar. 31, 2015		Dec. 31, 2014
In Thousands, unless otherwise specified
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	$14,439,574	[1]	$14,384,276	[1]
Real estate secured loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	1,861,689		1,764,519
Software and internet
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	4,871,574		4,954,676
Hardware
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	1,067,386		1,131,006
Private equity/venture capital
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	4,508,670		4,582,906
Life science & healthcare
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	1,399,449		1,289,904
Premium wine
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	799,184		794,321
Premium wine | Non-real Estate Secured Commercial Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	186,070		187,568
Premium wine | Real Estate Secured Commercial Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	613,114	[2]	606,753	[2]
Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	414,116		352,828
Other | Commercial Loans Receivable excluding Construction and Real Estate Secured
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	289,010		234,551
Other | Construction loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	85,684		78,626
Commercial Portfolio Segment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	13,060,379		13,105,641
Commercial Portfolio Segment | Commercial Loans Receivable excluding Construction and Real Estate Secured
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	12,322,159		12,380,611
Real estate secured loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	1,209,153		1,118,115
Real estate secured loans | Real estate secured loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	1,209,153	[3]	1,118,115	[3]
Other | Real Estate Secured Commercial Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	39,422		39,651
Consumer loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	$170,042		$160,520
[1]	Included within our total loan portfolio are credit card loans of $154 million and $131 million at March 31, 2015 and December 31, 2014, respectively.
[2]	Included in our premium wine portfolio are gross construction loans of $108 million and $112 million at March 31, 2015 and December 31, 2014, respectively.
[3]	Consumer loans secured by real estate at March 31, 2015 and December 31, 2014 were comprised of the following:(Dollars in thousands) March 31, 2015 December 31, 2014Loans for personal residence $1,001,125 $918,629Loans to eligible employees 139,761 133,568Home equity lines of credit 68,267 65,918Consumer loans secured by real estate $1,209,153 $1,118,115

Loans_and_Allowance_for_Loan_L4

Loans and Allowance for Loan Losses - Composition of Loans, Net of Unearned income (Additional Information) (Detail) (USD $)	Mar. 31, 2015		Dec. 31, 2014
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	$14,439,574,000	[1]	$14,384,276,000	[1]
Credit Card Receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loan portfolio	154,000,000		131,000,000
Real estate secured loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	1,209,153,000		1,118,115,000
Real estate secured loans | Loans for personal residence
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	1,001,125,000		918,629,000
Real estate secured loans | Loans to eligible employees
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	139,761,000		133,568,000
Real estate secured loans | Home equity lines of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	68,267,000		65,918,000
Premium wine
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross construction loans	108,000,000		112,000,000
Loans, net of unearned income	$799,184,000		$794,321,000
[1]	Included within our total loan portfolio are credit card loans of $154 million and $131 million at March 31, 2015 and December 31, 2014, respectively.

Loans_and_Allowance_for_Loan_L5

Loans and Allowance for Loan Losses - Composition of Loans, Net of Unearned Income, Broken Out by Portfolio Segment and Class of Financing Receivable (Detail) (USD $)	Mar. 31, 2015		Dec. 31, 2014
In Thousands, unless otherwise specified
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income	$14,439,574	[1]	$14,384,276	[1]
Software and internet
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income	4,871,574		4,954,676
Hardware
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income	1,067,386		1,131,006
Private equity/venture capital
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income	4,508,670		4,582,906
Life science & healthcare
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income	1,399,449		1,289,904
Premium wine
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income	799,184		794,321
Other
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income	414,116		352,828
Commercial Portfolio Segment
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income	13,060,379		13,105,641
Real estate secured loans
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income	1,209,153		1,118,115
Consumer loans
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income	170,042		160,520
Consumer Portfolio Segment
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income	$1,379,195		$1,278,635
[1]	Included within our total loan portfolio are credit card loans of $154 million and $131 million at March 31, 2015 and December 31, 2014, respectively.

Loans_and_Allowance_for_Loan_L6

Loans and Allowance for Loan Losses - Aging of Gross Loans, Broken out by Portfolio Segment and Class of Financing Receivable (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Accounts, Notes, Loans and Financing Receivable [Line Items]
30 - 59 Days Past Due	$19,710	$68,292
60 - 89 Days Past Due	15,861	4,176
Greater Than 90 Days Past Due	25,019	23,622
Total Past Due	60,590	96,090
Current	14,486,155	14,392,676
Loans Past Due 90 Days or More Still Accruing Interest	3,099	1,302
Software and internet
Accounts, Notes, Loans and Financing Receivable [Line Items]
30 - 59 Days Past Due	1,970	10,989
60 - 89 Days Past Due	162	1,627
Greater Than 90 Days Past Due	160	52
Total Past Due	2,292	12,668
Current	4,876,739	4,950,291
Loans Past Due 90 Days or More Still Accruing Interest	160	52
Hardware
Accounts, Notes, Loans and Financing Receivable [Line Items]
30 - 59 Days Past Due	298	13,424
60 - 89 Days Past Due	9,219	126
Greater Than 90 Days Past Due	0	0
Total Past Due	9,517	13,550
Current	1,066,598	1,124,423
Loans Past Due 90 Days or More Still Accruing Interest	0	0
Private equity/venture capital
Accounts, Notes, Loans and Financing Receivable [Line Items]
30 - 59 Days Past Due	11,462	40,773
60 - 89 Days Past Due	0	0
Greater Than 90 Days Past Due	0	0
Total Past Due	11,462	40,773
Current	4,536,175	4,580,526
Loans Past Due 90 Days or More Still Accruing Interest	0	0
Life science & healthcare
Accounts, Notes, Loans and Financing Receivable [Line Items]
30 - 59 Days Past Due	3,768	738
60 - 89 Days Past Due	0	786
Greater Than 90 Days Past Due	1,689	0
Total Past Due	5,457	1,524
Current	1,405,856	1,298,728
Loans Past Due 90 Days or More Still Accruing Interest	1,689	0
Premium wine
Accounts, Notes, Loans and Financing Receivable [Line Items]
30 - 59 Days Past Due	0	0
60 - 89 Days Past Due	0	0
Greater Than 90 Days Past Due	0	0
Total Past Due	0	0
Current	800,197	795,345
Loans Past Due 90 Days or More Still Accruing Interest	0	0
Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
30 - 59 Days Past Due	1,074	178
60 - 89 Days Past Due	0	3
Greater Than 90 Days Past Due	0	0
Total Past Due	1,074	181
Current	410,752	354,939
Loans Past Due 90 Days or More Still Accruing Interest	0	0
Commercial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
30 - 59 Days Past Due	18,572	66,102
60 - 89 Days Past Due	9,381	2,542
Greater Than 90 Days Past Due	1,849	52
Total Past Due	29,802	68,696
Current	13,096,317	13,104,252
Loans Past Due 90 Days or More Still Accruing Interest	1,849	52
Real estate secured loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
30 - 59 Days Past Due	415	1,592
60 - 89 Days Past Due	0	341
Greater Than 90 Days Past Due	1,250	1,250
Total Past Due	1,665	3,183
Current	1,206,762	1,114,286
Loans Past Due 90 Days or More Still Accruing Interest	1,250	1,250
Consumer loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
30 - 59 Days Past Due	410	0
60 - 89 Days Past Due	625	0
Greater Than 90 Days Past Due	0	0
Total Past Due	1,035	0
Current	168,782	160,212
Loans Past Due 90 Days or More Still Accruing Interest	0	0
Consumer loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
30 - 59 Days Past Due	825	1,592
60 - 89 Days Past Due	625	341
Greater Than 90 Days Past Due	1,250	1,250
Total Past Due	2,700	3,183
Current	1,375,544	1,274,498
Loans Past Due 90 Days or More Still Accruing Interest	1,250	1,250
Total gross loans excluding impaired loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
30 - 59 Days Past Due	19,397	67,694
60 - 89 Days Past Due	10,006	2,883
Greater Than 90 Days Past Due	3,099	1,302
Total Past Due	32,502	71,879
Current	14,471,861	14,378,750
Loans Past Due 90 Days or More Still Accruing Interest	3,099	1,302
Impaired loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
30 - 59 Days Past Due	313	598
60 - 89 Days Past Due	5,855	1,293
Greater Than 90 Days Past Due	21,920	22,320
Total Past Due	28,088	24,211
Current	14,294	13,926
Loans Past Due 90 Days or More Still Accruing Interest	$0	$0

Loans_and_Allowance_for_Loan_L7

Loans and Allowance for Loan Losses - Impaired Loans and Allowance for Loan Losses, Broken out by Portfolio Segment and Class of Financing Receivable (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Financing Receivable, Impaired [Line Items]
Carrying value of impaired loans	$42,382	$38,137
Total unpaid principal of impaired loans	46,791	42,899
Software and internet
Financing Receivable, Impaired [Line Items]
Carrying value of impaired loans	34,716	33,287
Total unpaid principal of impaired loans	35,027	34,218
Hardware
Financing Receivable, Impaired [Line Items]
Carrying value of impaired loans	510	2,521
Total unpaid principal of impaired loans	525	2,535
Private equity/venture capital
Financing Receivable, Impaired [Line Items]
Carrying value of impaired loans	0	0
Total unpaid principal of impaired loans	0	0
Life science & healthcare
Financing Receivable, Impaired [Line Items]
Carrying value of impaired loans	250	475
Total unpaid principal of impaired loans	2,453	2,453
Premium wine
Financing Receivable, Impaired [Line Items]
Carrying value of impaired loans	1,270	1,304
Total unpaid principal of impaired loans	1,734	1,743
Commercial loans
Financing Receivable, Impaired [Line Items]
Carrying value of impaired loans	42,102	37,820
Total unpaid principal of impaired loans	45,099	41,182
Other
Financing Receivable, Impaired [Line Items]
Carrying value of impaired loans	5,356	233
Total unpaid principal of impaired loans	5,360	233
Real estate secured loans
Financing Receivable, Impaired [Line Items]
Carrying value of impaired loans	210	192
Total unpaid principal of impaired loans	1,438	1,412
Consumer loans
Financing Receivable, Impaired [Line Items]
Carrying value of impaired loans	70	125
Total unpaid principal of impaired loans	254	305
Consumer loans
Financing Receivable, Impaired [Line Items]
Carrying value of impaired loans	280	317
Total unpaid principal of impaired loans	1,692	1,717
Impaired loans for which there is a related allowance for loan losses
Financing Receivable, Impaired [Line Items]
Carrying value of impaired loans	40,932	35,523
Impaired loans for which there is a related allowance for loan losses | Software and internet
Financing Receivable, Impaired [Line Items]
Carrying value of impaired loans	34,716	33,287
Impaired loans for which there is a related allowance for loan losses | Hardware
Financing Receivable, Impaired [Line Items]
Carrying value of impaired loans	510	1,403
Impaired loans for which there is a related allowance for loan losses | Private equity/venture capital
Financing Receivable, Impaired [Line Items]
Carrying value of impaired loans	0	0
Impaired loans for which there is a related allowance for loan losses | Life science & healthcare
Financing Receivable, Impaired [Line Items]
Carrying value of impaired loans	250	475
Impaired loans for which there is a related allowance for loan losses | Premium wine
Financing Receivable, Impaired [Line Items]
Carrying value of impaired loans	0	0
Impaired loans for which there is a related allowance for loan losses | Commercial loans
Financing Receivable, Impaired [Line Items]
Carrying value of impaired loans	40,832	35,398
Impaired loans for which there is a related allowance for loan losses | Other
Financing Receivable, Impaired [Line Items]
Carrying value of impaired loans	5,356	233
Impaired loans for which there is a related allowance for loan losses | Real estate secured loans
Financing Receivable, Impaired [Line Items]
Carrying value of impaired loans	30	0
Impaired loans for which there is a related allowance for loan losses | Consumer loans
Financing Receivable, Impaired [Line Items]
Carrying value of impaired loans	70	125
Impaired loans for which there is a related allowance for loan losses | Consumer loans
Financing Receivable, Impaired [Line Items]
Carrying value of impaired loans	100	125
Impaired loans for which there is no related allowance for loan losses
Financing Receivable, Impaired [Line Items]
Carrying value of impaired loans	1,450	2,614
Impaired loans for which there is no related allowance for loan losses | Software and internet
Financing Receivable, Impaired [Line Items]
Carrying value of impaired loans	0	0
Impaired loans for which there is no related allowance for loan losses | Hardware
Financing Receivable, Impaired [Line Items]
Carrying value of impaired loans	0	1,118
Impaired loans for which there is no related allowance for loan losses | Private equity/venture capital
Financing Receivable, Impaired [Line Items]
Carrying value of impaired loans	0	0
Impaired loans for which there is no related allowance for loan losses | Life science & healthcare
Financing Receivable, Impaired [Line Items]
Carrying value of impaired loans	0	0
Impaired loans for which there is no related allowance for loan losses | Premium wine
Financing Receivable, Impaired [Line Items]
Carrying value of impaired loans	1,270	1,304
Impaired loans for which there is no related allowance for loan losses | Commercial loans
Financing Receivable, Impaired [Line Items]
Carrying value of impaired loans	1,270	2,422
Impaired loans for which there is no related allowance for loan losses | Other
Financing Receivable, Impaired [Line Items]
Carrying value of impaired loans	0	0
Impaired loans for which there is no related allowance for loan losses | Real estate secured loans
Financing Receivable, Impaired [Line Items]
Carrying value of impaired loans	180	192
Impaired loans for which there is no related allowance for loan losses | Consumer loans
Financing Receivable, Impaired [Line Items]
Carrying value of impaired loans	0	0
Impaired loans for which there is no related allowance for loan losses | Consumer loans
Financing Receivable, Impaired [Line Items]
Carrying value of impaired loans	$180	$192

Loans_and_Allowance_for_Loan_L8

Loans and Allowance for Loan Losses - Average Impaired Loans, Broken out by Portfolio Segment and Class of Financing Receivable (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Financing Receivable, Impaired [Line Items]
Average impaired loans	$39,472	$35,655
Software and internet
Financing Receivable, Impaired [Line Items]
Average impaired loans	33,725	14,677
Hardware
Financing Receivable, Impaired [Line Items]
Average impaired loans	1,643	16,020
Life science & healthcare
Financing Receivable, Impaired [Line Items]
Average impaired loans	400	1,022
Premium wine
Financing Receivable, Impaired [Line Items]
Average impaired loans	1,282	1,433
Other
Financing Receivable, Impaired [Line Items]
Average impaired loans	2,139	1,777
Commercial loans
Financing Receivable, Impaired [Line Items]
Average impaired loans	39,189	34,929
Real estate secured loans
Financing Receivable, Impaired [Line Items]
Average impaired loans	195	237
Consumer loans
Financing Receivable, Impaired [Line Items]
Average impaired loans	88	489
Consumer loans
Financing Receivable, Impaired [Line Items]
Average impaired loans	$283	$726

Loans_and_Allowance_for_Loan_L9

Loans and Allowance for Loan Losses - Activity in Allowance for Loan Losses Broken out by Portfolio Segment (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance	$165,359	$142,886
Charge-offs	-5,487	-21,150
Recoveries	1,551	1,312
Provision for (Reduction of) Loan Losses	6,452	494
Ending Balance	167,875	123,542
Software and internet
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance	80,981	64,084
Charge-offs	-1,403	-8,010
Recoveries	447	114
Provision for (Reduction of) Loan Losses	2,067	-947
Ending Balance	82,092	55,241
Hardware
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance	25,860	36,553
Charge-offs	-3,210	-12,175
Recoveries	928	775
Provision for (Reduction of) Loan Losses	-2,320	83
Ending Balance	21,258	25,236
Private equity/venture capital
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance	27,997	16,385
Charge-offs	0	0
Recoveries	0	0
Provision for (Reduction of) Loan Losses	2,840	1,291
Ending Balance	30,837	17,676
Life science & healthcare
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance	15,208	11,926
Charge-offs	-225	-681
Recoveries	34	98
Provision for (Reduction of) Loan Losses	306	131
Ending Balance	15,323	11,474
Premium wine
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance	4,473	3,914
Charge-offs	0	0
Recoveries	0	219
Provision for (Reduction of) Loan Losses	30	-396
Ending Balance	4,503	3,737
Other
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance	3,253	3,680
Charge-offs	-649	-284
Recoveries	10	0
Provision for (Reduction of) Loan Losses	3,537	645
Ending Balance	6,151	4,041
Commercial loans
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance	157,772	136,542
Charge-offs	-5,487	-21,150
Recoveries	1,419	1,206
Provision for (Reduction of) Loan Losses	6,460	807
Ending Balance	160,164	117,405
Consumer loans
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance	7,587	6,344
Charge-offs	0	0
Recoveries	132	106
Provision for (Reduction of) Loan Losses	-8	-313
Ending Balance	$7,711	$6,137

Recovered_Sheet1

Loans and Allowance for Loan Losses - Allowance for Loan Losses Individually and Collectively Evaluated for Impairment (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Financing Receivable, Impaired [Line Items]
Individually Evaluated for Impairment, Allowance for loan losses	$23,822	$15,051
Individually Evaluated for Impairment, Recorded investment in loans	42,382	38,137
Collectively Evaluated for Impairment, Allowance for loan losses	144,053	150,308
Collectively Evaluated for Impairment, Allowance for loan losses	14,397,192	14,346,139
Software and internet
Financing Receivable, Impaired [Line Items]
Individually Evaluated for Impairment, Allowance for loan losses	20,942	13,695
Individually Evaluated for Impairment, Recorded investment in loans	34,716	33,287
Collectively Evaluated for Impairment, Allowance for loan losses	61,150	67,286
Collectively Evaluated for Impairment, Allowance for loan losses	4,836,858	4,921,389
Hardware
Financing Receivable, Impaired [Line Items]
Individually Evaluated for Impairment, Allowance for loan losses	12	1,133
Individually Evaluated for Impairment, Recorded investment in loans	510	2,521
Collectively Evaluated for Impairment, Allowance for loan losses	21,246	24,727
Collectively Evaluated for Impairment, Allowance for loan losses	1,066,876	1,128,485
Private equity/venture capital
Financing Receivable, Impaired [Line Items]
Individually Evaluated for Impairment, Allowance for loan losses	0	0
Individually Evaluated for Impairment, Recorded investment in loans	0	0
Collectively Evaluated for Impairment, Allowance for loan losses	30,837	27,997
Collectively Evaluated for Impairment, Allowance for loan losses	4,508,670	4,582,906
Life science & healthcare
Financing Receivable, Impaired [Line Items]
Individually Evaluated for Impairment, Allowance for loan losses	63	121
Individually Evaluated for Impairment, Recorded investment in loans	250	475
Collectively Evaluated for Impairment, Allowance for loan losses	15,260	15,087
Collectively Evaluated for Impairment, Allowance for loan losses	1,399,199	1,289,429
Premium wine
Financing Receivable, Impaired [Line Items]
Individually Evaluated for Impairment, Allowance for loan losses	0	0
Individually Evaluated for Impairment, Recorded investment in loans	1,270	1,304
Collectively Evaluated for Impairment, Allowance for loan losses	4,503	4,473
Collectively Evaluated for Impairment, Allowance for loan losses	797,914	793,017
Other
Financing Receivable, Impaired [Line Items]
Individually Evaluated for Impairment, Allowance for loan losses	2,705	71
Individually Evaluated for Impairment, Recorded investment in loans	5,356	233
Collectively Evaluated for Impairment, Allowance for loan losses	3,446	3,182
Collectively Evaluated for Impairment, Allowance for loan losses	408,760	352,595
Commercial loans
Financing Receivable, Impaired [Line Items]
Individually Evaluated for Impairment, Allowance for loan losses	23,722	15,020
Individually Evaluated for Impairment, Recorded investment in loans	42,102	37,820
Collectively Evaluated for Impairment, Allowance for loan losses	136,442	142,752
Collectively Evaluated for Impairment, Allowance for loan losses	13,018,277	13,067,821
Consumer loans
Financing Receivable, Impaired [Line Items]
Individually Evaluated for Impairment, Allowance for loan losses	100	31
Individually Evaluated for Impairment, Recorded investment in loans	280	317
Collectively Evaluated for Impairment, Allowance for loan losses	7,611	7,556
Collectively Evaluated for Impairment, Allowance for loan losses	$1,378,915	$1,278,318

Recovered_Sheet2

Loans and Allowance for Loan Losses - Credit Quality Indicators, Broken out by Portfolio Segment and Class of Financing Receivables (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Financing Receivable, Recorded Investment [Line Items]
Financing receivable	$14,546,745	$14,488,766
Software and internet
Financing Receivable, Recorded Investment [Line Items]
Financing receivable	4,913,747	4,996,246
Hardware
Financing Receivable, Recorded Investment [Line Items]
Financing receivable	1,076,625	1,140,494
Private equity/venture capital
Financing Receivable, Recorded Investment [Line Items]
Financing receivable	4,547,637	4,621,299
Life science & healthcare
Financing Receivable, Recorded Investment [Line Items]
Financing receivable	1,411,563	1,300,727
Premium wine
Financing Receivable, Recorded Investment [Line Items]
Financing receivable	801,467	796,649
Other
Financing Receivable, Recorded Investment [Line Items]
Financing receivable	417,182	355,353
Commercial loans
Financing Receivable, Recorded Investment [Line Items]
Financing receivable	13,168,221	13,210,768
Real estate secured loans
Financing Receivable, Recorded Investment [Line Items]
Financing receivable	1,208,637	1,117,661
Consumer loans
Financing Receivable, Recorded Investment [Line Items]
Financing receivable	169,887	160,337
Consumer loans
Financing Receivable, Recorded Investment [Line Items]
Financing receivable	1,378,524	1,277,998
Pass
Financing Receivable, Recorded Investment [Line Items]
Financing receivable	13,734,381	13,729,421
Pass | Software and internet
Financing Receivable, Recorded Investment [Line Items]
Financing receivable	4,483,199	4,611,253
Pass | Hardware
Financing Receivable, Recorded Investment [Line Items]
Financing receivable	874,295	945,998
Pass | Private equity/venture capital
Financing Receivable, Recorded Investment [Line Items]
Financing receivable	4,543,600	4,615,231
Pass | Life science & healthcare
Financing Receivable, Recorded Investment [Line Items]
Financing receivable	1,282,275	1,165,266
Pass | Premium wine
Financing Receivable, Recorded Investment [Line Items]
Financing receivable	780,710	774,962
Pass | Other
Financing Receivable, Recorded Investment [Line Items]
Financing receivable	404,481	346,153
Pass | Commercial loans
Financing Receivable, Recorded Investment [Line Items]
Financing receivable	12,368,560	12,458,863
Pass | Real estate secured loans
Financing Receivable, Recorded Investment [Line Items]
Financing receivable	1,199,907	1,112,396
Pass | Consumer loans
Financing Receivable, Recorded Investment [Line Items]
Financing receivable	165,914	158,162
Pass | Consumer loans
Financing Receivable, Recorded Investment [Line Items]
Financing receivable	1,365,821	1,270,558
Performing (Criticized)
Financing Receivable, Recorded Investment [Line Items]
Financing receivable	769,982	721,208
Performing (Criticized) | Software and internet
Financing Receivable, Recorded Investment [Line Items]
Financing receivable	395,832	351,706
Performing (Criticized) | Hardware
Financing Receivable, Recorded Investment [Line Items]
Financing receivable	201,820	191,975
Performing (Criticized) | Private equity/venture capital
Financing Receivable, Recorded Investment [Line Items]
Financing receivable	4,037	6,068
Performing (Criticized) | Life science & healthcare
Financing Receivable, Recorded Investment [Line Items]
Financing receivable	129,038	134,986
Performing (Criticized) | Premium wine
Financing Receivable, Recorded Investment [Line Items]
Financing receivable	19,487	20,383
Performing (Criticized) | Other
Financing Receivable, Recorded Investment [Line Items]
Financing receivable	7,345	8,967
Performing (Criticized) | Commercial loans
Financing Receivable, Recorded Investment [Line Items]
Financing receivable	757,559	714,085
Performing (Criticized) | Real estate secured loans
Financing Receivable, Recorded Investment [Line Items]
Financing receivable	8,520	5,073
Performing (Criticized) | Consumer loans
Financing Receivable, Recorded Investment [Line Items]
Financing receivable	3,903	2,050
Performing (Criticized) | Consumer loans
Financing Receivable, Recorded Investment [Line Items]
Financing receivable	12,423	7,123
Impaired
Financing Receivable, Recorded Investment [Line Items]
Financing receivable	42,382	38,137
Impaired | Software and internet
Financing Receivable, Recorded Investment [Line Items]
Financing receivable	34,716	33,287
Impaired | Hardware
Financing Receivable, Recorded Investment [Line Items]
Financing receivable	510	2,521
Impaired | Private equity/venture capital
Financing Receivable, Recorded Investment [Line Items]
Financing receivable	0	0
Impaired | Life science & healthcare
Financing Receivable, Recorded Investment [Line Items]
Financing receivable	250	475
Impaired | Premium wine
Financing Receivable, Recorded Investment [Line Items]
Financing receivable	1,270	1,304
Impaired | Other
Financing Receivable, Recorded Investment [Line Items]
Financing receivable	5,356	233
Impaired | Commercial loans
Financing Receivable, Recorded Investment [Line Items]
Financing receivable	42,102	37,820
Impaired | Real estate secured loans
Financing Receivable, Recorded Investment [Line Items]
Financing receivable	210	192
Impaired | Consumer loans
Financing Receivable, Recorded Investment [Line Items]
Financing receivable	70	125
Impaired | Consumer loans
Financing Receivable, Recorded Investment [Line Items]
Financing receivable	$280	$317

Recovered_Sheet3

Loans and Allowance for Loan Losses - Summary of Loans Modified in Troubled Debt Restructurings ("TDRs") by Portfolio Segment and Class of Financing Receivables (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015		Mar. 31, 2014		Dec. 31, 2014
	troubled_debt_restructuring
Financing Receivable, Modifications [Line Items]
Number of troubled debt restructurings	9
Loans modified in TDRs	$10,588				$7,151
Loans modified in TDRs during the period	5,280	[1]	12,133	[1]
Software and internet
Financing Receivable, Modifications [Line Items]
Loans modified in TDRs	2,707				3,784
Loans modified in TDRs during the period	0		9,737
Hardware
Financing Receivable, Modifications [Line Items]
Loans modified in TDRs	4,510				1,118
Loans modified in TDRs during the period	4,000		0
Premium wine
Financing Receivable, Modifications [Line Items]
Loans modified in TDRs	1,830				1,891
Loans modified in TDRs during the period	0		650
Other
Financing Receivable, Modifications [Line Items]
Loans modified in TDRs	191				233
Loans modified in TDRs during the period	0		1,746
Commercial loans
Financing Receivable, Modifications [Line Items]
Loans modified in TDRs	9,238				7,026
Loans modified in TDRs during the period	4,000		12,133
Real estate secured loans
Financing Receivable, Modifications [Line Items]
Loans modified in TDRs during the period	1,280		0
Consumer loans
Financing Receivable, Modifications [Line Items]
Loans modified in TDRs	1,350				125
Consumer loans
Financing Receivable, Modifications [Line Items]
Loans modified in TDRs	1,350				125
Loans modified in TDRs during the period	1,280		0
Payment Deferrals Granted
Financing Receivable, Modifications [Line Items]
Loans modified in TDRs during the period			9,300
Forgiveness of Principal
Financing Receivable, Modifications [Line Items]
Loans modified in TDRs during the period			$2,800
[1]	There were no partial charge-offs on loans classified as TDRs during the three months ended March 31, 2015 or March 31, 2014.

Recovered_Sheet4

Loans and Allowance for Loan Losses - Recorded Investment in Loans Modified in TDRs (Detail) (USD $)	3 Months Ended
	Mar. 31, 2015		Mar. 31, 2014
Financing Receivable, Modifications [Line Items]
TDRs modified within the previous 12 months that defaulted during the period	$30,000
Loans modified in TDRs during the period	5,280,000	[1]	12,133,000	[1]
Loans classified as TDRs, charge-offs	0
Software and internet
Financing Receivable, Modifications [Line Items]
Loans modified in TDRs during the period	0		9,737,000
Hardware
Financing Receivable, Modifications [Line Items]
Loans modified in TDRs during the period	4,000,000		0
Premium wine
Financing Receivable, Modifications [Line Items]
Loans modified in TDRs during the period	0		650,000
Other
Financing Receivable, Modifications [Line Items]
Loans modified in TDRs during the period	0		1,746,000
Commercial loans
Financing Receivable, Modifications [Line Items]
Loans modified in TDRs during the period	4,000,000		12,133,000
Real estate secured loans
Financing Receivable, Modifications [Line Items]
TDRs modified within the previous 12 months that defaulted during the period	30,000
Loans modified in TDRs during the period	1,280,000		0
Consumer loans
Financing Receivable, Modifications [Line Items]
Loans modified in TDRs during the period	1,280,000		0
Payment Deferrals Granted
Financing Receivable, Modifications [Line Items]
Loans modified in TDRs during the period			$9,300,000
[1]	There were no partial charge-offs on loans classified as TDRs during the three months ended March 31, 2015 or March 31, 2014.

Disposal_Assets_HeldforSale_De

Disposal - Assets Held-for-Sale (Details) (SVB India Finance Private Limited, (SVBIF), USD $)	Mar. 31, 2015		Dec. 31, 2014
In Thousands, unless otherwise specified
Global Commercial Bank
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Total assets of SVBIF held-for-sale	$48,200		$44,300
Disposal Group, Held-for-sale, Not Discontinued Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash and due from banks	2,897		3,054
Securities purchased under agreement to resell and other short-term investments	6,419		11,898
Net loans	33,276		26,800
Premises and equipment, net	24		24
Accrued interest receivable and other assets	10,307		7,163
Total assets of SVBIF held-for-sale	52,923	[1]	48,939	[1]
Other liabilities	4,723		4,686
Total liabilities of SVBIF held-for-sale	$4,723	[1]	$4,686	[1]
[1]	Net assets of $48.2 million and $44.3 million are included in our Global Commercial Bank operating segment as reported in Note 11—”Segment Reporting” of the “Notes to Interim Consolidated Financial Statements” under Part I, Item 1 of this report.

ShortTerm_Borrowings_and_LongT2

Short-Term Borrowings and Long-Term Debt - Outstanding Short Term Borrowings and Long Term Debt (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015		Jan. 29, 2015	Dec. 31, 2014
Debt Outstanding [Line Items]
Federal Home Loan Bank Advances	$60,000			$0
Short-term borrowings	77,766			7,781
Total long-term debt	802,917			453,443
Federal Home Loan Bank Advances
Debt Outstanding [Line Items]
Maturity	1-Apr-15
Debt Instrument, Face Amount	60,000
Other short-term borrowings
Debt Outstanding [Line Items]
Debt Instrument, Face Amount	17,766	[1]
Short-term borrowings	17,766	[1]		7,781	[1]
Senior Notes Three Point Five Zero Percent Due January Twenty Twenty Five [Member]
Debt Outstanding [Line Items]
Maturity	29-Jan-25
Debt Instrument, Face Amount	350,000		350,000
Senior Notes	349,710			0
5.375% Senior Notes
Debt Outstanding [Line Items]
Maturity	15-Sep-20
Debt Instrument, Face Amount	350,000
Senior Notes	348,495			348,436
6.05% Subordinated Notes
Debt Outstanding [Line Items]
Maturity	1-Jun-17	[2]
Debt Instrument, Face Amount	45,964	[2]
Subordinated Notes	49,910	[2]		50,162	[2]
7.0% Junior Subordinated Debentures
Debt Outstanding [Line Items]
Maturity	15-Oct-33
Debt Instrument, Face Amount	50,000
Junior Subordinated Debentures	$54,802			$54,845
[1]	Represents cash collateral received from certain counterparties in relation to market value exposures of derivative contracts in our favor, which includes an interest rate swap agreement related to our 6.05% Subordinated Notes.
[2]	At March 31, 2015 and December 31, 2014, included in the carrying value of our 6.05% Subordinated Notes was an interest rate swap valued at $4.3 million and $4.6 million, respectively, related to hedge accounting associated with the notes.

ShortTerm_Borrowings_and_LongT3

Short-Term Borrowings and Long-Term Debt - Outstanding Short Term Borrowings and Long Term Debt (Additional Information) (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Senior Notes Three Point Five Zero Percent Due January Twenty Twenty Five [Member]
Debt Outstanding [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.50%
5.375% Senior Notes
Debt Outstanding [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	5.38%	5.38%
6.05% Subordinated Notes
Debt Outstanding [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	6.05%	6.05%
Fair value of the interest rate swap associated with the notes	4,300	4,600
7.0% Junior Subordinated Debentures
Debt Outstanding [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	7.00%	7.00%
Estimated Fair Value | 6.05% Subordinated Notes
Debt Outstanding [Line Items]
Fair value of the interest rate swap associated with the notes	4,300

ShortTerm_Borrowings_and_LongT4

Short-Term Borrowings and Long-Term Debt - Additional Information (Detail) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014	Jan. 29, 2015
Debt Disclosure [Line Items]
Interest expense on debt	$8,000,000	$5,800,000
Weighted average interest rates associated with short-term borrowings	0.19%
Federal Home Loan Bank Advances	60,000,000		0
Proceeds from issuance of 3.50% Senior Notes	346,431,000	0
Senior Notes Three Point Five Zero Percent Due January Twenty Twenty Five [Member]
Debt Disclosure [Line Items]
Debt Instrument, Unamortized Discount	300,000
Debt Instrument, Face Amount	350,000,000			350,000,000
5.375% Senior Notes
Debt Disclosure [Line Items]
Debt Instrument, Face Amount	350,000,000
Proceeds from issuance of 3.50% Senior Notes	346,400,000
Federal Home Loan Bank Advances
Debt Disclosure [Line Items]
Market value of collateral pledged	1,300,000,000
Debt Instrument, Face Amount	60,000,000
Federal Reserve Bank Advances
Debt Disclosure [Line Items]
Market value of collateral pledged	$979,000,000

Derivative_Financial_Instrumen2

Derivative Financial Instruments - Total Notional or Contractual Amounts, Fair Value, Collateral and Net Exposure of Derivative Financial Instruments (Detail) (USD $)	Mar. 31, 2015		Dec. 31, 2014
In Thousands, unless otherwise specified
Derivative [Line Items]
Fair Value	$137,305		$126,879
Net Exposure	119,539	[1]	119,098	[1]
Collateral	17,766	[2]	7,781	[2]
Derivatives designated as hedging instruments | Interest rate risks | Interest rate swaps | Other assets
Derivative [Line Items]
Notional or Contractual Amount	45,964		45,964
Fair Value	4,340		4,609
Net Exposure	1,370	[1]	1,639	[1]
Collateral	2,970	[2]	2,970	[2]
Derivatives not designated as hedging instruments | Currency exchange risks
Derivative [Line Items]
Fair Value	8,011		4,561
Net Exposure	2,873	[1]	2,120	[1]
Collateral	5,138	[2]	2,441	[2]
Derivatives not designated as hedging instruments | Currency exchange risks | Foreign exchange forwards | Other assets
Derivative [Line Items]
Notional or Contractual Amount	179,467		200,957
Fair Value	8,688		5,050
Net Exposure	3,550	[1]	2,609	[1]
Collateral	5,138	[2]	2,441	[2]
Derivatives not designated as hedging instruments | Currency exchange risks | Foreign exchange forwards | Other liability
Derivative [Line Items]
Notional or Contractual Amount	3,916		6,226
Fair Value	-677		-489
Net Exposure	-677	[1]	-489	[1]
Collateral	0	[2]	0	[2]
Derivatives not designated as hedging instruments | Other derivative instruments | Equity warrant assets | Other assets
Derivative [Line Items]
Notional or Contractual Amount	198,864		197,878
Fair Value	124,456		116,604
Net Exposure	124,456	[1]	116,604	[1]
Collateral	0	[2]	0	[2]
Derivatives not designated as hedging instruments | Other derivative instruments | Other derivatives
Derivative [Line Items]
Fair Value	498		1,105
Net Exposure	-9,160	[1]	-1,265	[1]
Collateral	9,658	[2]	2,370	[2]
Derivatives not designated as hedging instruments | Other derivative instruments | Other derivatives | Foreign exchange forwards | Other assets
Derivative [Line Items]
Notional or Contractual Amount	772,019		801,487
Fair Value	45,284		28,954
Net Exposure	35,626	[1]	26,584	[1]
Collateral	9,658	[2]	2,370	[2]
Derivatives not designated as hedging instruments | Other derivative instruments | Other derivatives | Foreign exchange forwards | Other liability
Derivative [Line Items]
Notional or Contractual Amount	694,943		774,355
Fair Value	-44,527		-27,647
Net Exposure	-44,527	[1]	-27,647	[1]
Collateral	0	[2]	0	[2]
Derivatives not designated as hedging instruments | Other derivative instruments | Other derivatives | Client foreign currency options | Other assets
Derivative [Line Items]
Notional or Contractual Amount	51,483		34,926
Fair Value	523		227
Net Exposure	523	[1]	227	[1]
Collateral	0	[2]	0	[2]
Derivatives not designated as hedging instruments | Other derivative instruments | Other derivatives | Client foreign currency options | Other liability
Derivative [Line Items]
Notional or Contractual Amount	51,483		34,926
Fair Value	-523		-227
Net Exposure	-523	[1]	-227	[1]
Collateral	0	[2]	0	[2]
Derivatives not designated as hedging instruments | Other derivative instruments | Other derivatives | Client interest rate derivatives | Other assets
Derivative [Line Items]
Notional or Contractual Amount	377,530		387,410
Fair Value	2,907		2,546
Net Exposure	2,907	[1]	2,546	[1]
Collateral	0	[2]	0	[2]
Derivatives not designated as hedging instruments | Other derivative instruments | Other derivatives | Client interest rate derivatives | Other liability
Derivative [Line Items]
Notional or Contractual Amount	377,530		387,410
Fair Value	-3,166		-2,748
Net Exposure	-3,166	[1]	-2,748	[1]
Collateral	$0	[2]	$0	[2]
[1]	Net exposure for contracts in a gain position reflects the replacement cost in the event of nonperformance by all such counterparties. The credit ratings of our institutional counterparties as of March 31, 2015 remain at investment grade or higher and there were no material changes in their credit ratings during the three months ended March 31, 2015.
[2]	Cash collateral received from our counterparties in relation to market value exposures of derivative contracts in our favor is recorded as a component of “short-term borrowings” on our consolidated balance sheets.

Derivative_Financial_Instrumen3

Derivative Financial Instruments - Summary of Derivative Activity and Related Impact on Consolidated Statements of Income (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015		Mar. 31, 2014
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized gain (loss) on derivatives	$20,404		($13,356)
Derivatives designated as hedging instruments | Interest rate risks | Interest rate swaps | Interest expense—borrowings
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized gain (loss) on derivatives	638		639
Derivatives designated as hedging instruments | Interest rate risks | Interest rate swaps | Gain (Loss) on Derivative Instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized gain (loss) on derivatives	-3		-12
Derivatives designated as hedging instruments | Interest rate risks | Interest Rate Risk
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized gain (loss) on derivatives	635		627
Derivatives not designated as hedging instruments | Currency exchange risks
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized gain (loss) on derivatives	-141		-51
Derivatives not designated as hedging instruments | Currency exchange risks | Loans | Other noninterest income
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized gain (loss) on derivatives	-20,159		978
Derivatives not designated as hedging instruments | Currency exchange risks | Foreign exchange forwards | Gain (Loss) on Derivative Instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized gain (loss) on derivatives	20,018		-1,029
Derivatives not designated as hedging instruments | Other derivative instruments | Foreign exchange forwards | Gain (Loss) on Derivative Instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized gain (loss) on derivatives	-507		302
Derivatives not designated as hedging instruments | Other derivative instruments | Equity warrant assets | Gain (Loss) on Derivative Instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized gain (loss) on derivatives	20,278		25,373
Derivatives not designated as hedging instruments | Other derivative instruments | Other derivatives | Gain (Loss) on Derivative Instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized gain (loss) on derivatives	($57)	[1]	($467)	[1]
[1]	Primarily represents the change in fair value of loan conversion options

Derivative_Financial_Instrumen4

Derivative Financial Instruments - Master Netting Arrangements (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Assets and Liabilities Subject to Master Netting Arrangements [Line Items]
Gross Amounts of Recognized Assets	$298,052	$137,271
Gross Amounts offset in the Statement of Financial Position	-283	-274
Net Amounts of Assets Presented in the Statement of Financial Position	297,769	136,997
Gross Assets Subject To Master Netting Arrangement Not Offset	-265,184	-117,783
Cash Collateral Received Subject to Master Netting Arrangements	-17,766	-7,781
Net Assets After Deducting Amounts Subject to Master Netting Arrangements	14,819	11,433
Gross Amounts of Recognized Liabilities	49,176	31,385
Gross Amounts offset in the Statement of Financial Position	-283	-274
Net Amounts of Liabilities Presented in the Statement of Financial Position	48,893	31,111
Gross Liabilities Subject To Master Netting Arrangement Not Offset	-11,903	-19,639
Cash Collateral Pledged Subject to Master Netting Arrangements	0	0
Net Liabilities After Deducting Amounts Subject to Master Netting Arrangements	36,990	11,472
Derivative
Assets and Liabilities Subject to Master Netting Arrangements [Line Items]
Gross Amounts of Recognized Assets	62,025	41,660
Gross Amounts offset in the Statement of Financial Position	-283	-274
Net Amounts of Assets Presented in the Statement of Financial Position	61,742	41,386
Gross Assets Subject To Master Netting Arrangement Not Offset	-29,157	-22,172
Cash Collateral Received Subject to Master Netting Arrangements	-17,766	-7,781
Net Assets After Deducting Amounts Subject to Master Netting Arrangements	14,819	11,433
Gross Amounts of Recognized Liabilities	49,176	31,385
Gross Amounts offset in the Statement of Financial Position	-283	-274
Net Amounts of Liabilities Presented in the Statement of Financial Position	48,893	31,111
Gross Liabilities Subject To Master Netting Arrangement Not Offset	-11,903	-19,639
Cash Collateral Pledged Subject to Master Netting Arrangements	0	0
Net Liabilities After Deducting Amounts Subject to Master Netting Arrangements	36,990	11,472
Derivative | Interest rate swaps
Assets and Liabilities Subject to Master Netting Arrangements [Line Items]
Gross Amounts of Recognized Assets	4,340	4,609
Gross Amounts offset in the Statement of Financial Position	0	0
Net Amounts of Assets Presented in the Statement of Financial Position	4,340	4,609
Gross Assets Subject To Master Netting Arrangement Not Offset	-1,370	-1,639
Cash Collateral Received Subject to Master Netting Arrangements	-2,970	-2,970
Net Assets After Deducting Amounts Subject to Master Netting Arrangements	0	0
Derivative | Foreign exchange forwards
Assets and Liabilities Subject to Master Netting Arrangements [Line Items]
Gross Amounts of Recognized Assets	53,972	34,004
Gross Amounts offset in the Statement of Financial Position	0	0
Net Amounts of Assets Presented in the Statement of Financial Position	53,972	34,004
Gross Assets Subject To Master Netting Arrangement Not Offset	-24,627	-17,843
Cash Collateral Received Subject to Master Netting Arrangements	-14,796	-4,811
Net Assets After Deducting Amounts Subject to Master Netting Arrangements	14,549	11,350
Gross Amounts of Recognized Liabilities	45,204	28,136
Gross Amounts offset in the Statement of Financial Position	0	0
Net Amounts of Liabilities Presented in the Statement of Financial Position	45,204	28,136
Gross Liabilities Subject To Master Netting Arrangement Not Offset	-8,467	-16,808
Cash Collateral Pledged Subject to Master Netting Arrangements	0	0
Net Liabilities After Deducting Amounts Subject to Master Netting Arrangements	36,737	11,328
Derivative | Client foreign currency options
Assets and Liabilities Subject to Master Netting Arrangements [Line Items]
Gross Amounts of Recognized Assets	806	501
Gross Amounts offset in the Statement of Financial Position	-283	-274
Net Amounts of Assets Presented in the Statement of Financial Position	523	227
Gross Assets Subject To Master Netting Arrangement Not Offset	-253	-144
Cash Collateral Received Subject to Master Netting Arrangements	0	0
Net Assets After Deducting Amounts Subject to Master Netting Arrangements	270	83
Gross Amounts of Recognized Liabilities	806	501
Gross Amounts offset in the Statement of Financial Position	-283	-274
Net Amounts of Liabilities Presented in the Statement of Financial Position	523	227
Gross Liabilities Subject To Master Netting Arrangement Not Offset	-270	-83
Cash Collateral Pledged Subject to Master Netting Arrangements	0	0
Net Liabilities After Deducting Amounts Subject to Master Netting Arrangements	253	144
Derivative | Client interest rate derivatives
Assets and Liabilities Subject to Master Netting Arrangements [Line Items]
Gross Amounts of Recognized Assets	2,907	2,546
Gross Amounts offset in the Statement of Financial Position	0	0
Net Amounts of Assets Presented in the Statement of Financial Position	2,907	2,546
Gross Assets Subject To Master Netting Arrangement Not Offset	-2,907	-2,546
Cash Collateral Received Subject to Master Netting Arrangements	0	0
Net Assets After Deducting Amounts Subject to Master Netting Arrangements	0	0
Gross Amounts of Recognized Liabilities	3,166	2,748
Gross Amounts offset in the Statement of Financial Position	0	0
Net Amounts of Liabilities Presented in the Statement of Financial Position	3,166	2,748
Gross Liabilities Subject To Master Netting Arrangement Not Offset	-3,166	-2,748
Cash Collateral Pledged Subject to Master Netting Arrangements	0	0
Net Liabilities After Deducting Amounts Subject to Master Netting Arrangements	0	0
Reverse Repurchase Securities Borrowing And Similar Arrangements
Assets and Liabilities Subject to Master Netting Arrangements [Line Items]
Gross Amounts of Recognized Assets	236,027	95,611
Gross Amounts offset in the Statement of Financial Position	0	0
Net Amounts of Assets Presented in the Statement of Financial Position	236,027	95,611
Gross Assets Subject To Master Netting Arrangement Not Offset	-236,027	-95,611
Cash Collateral Received Subject to Master Netting Arrangements	0	0
Net Assets After Deducting Amounts Subject to Master Netting Arrangements	0	0
Gross Amounts of Recognized Liabilities	0	0
Gross Amounts offset in the Statement of Financial Position	0	0
Net Amounts of Liabilities Presented in the Statement of Financial Position	0	0
Gross Liabilities Subject To Master Netting Arrangement Not Offset	0	0
Cash Collateral Pledged Subject to Master Netting Arrangements	0	0
Net Liabilities After Deducting Amounts Subject to Master Netting Arrangements	$0	$0

Other_Noninterest_Loss_Income_2

Other Noninterest (Loss) Income and Other Noninterest Expense - Summary of Other Noninterest Income (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015		Mar. 31, 2014
Other Income and Expenses [Abstract]
Fund management fees	$3,722		$2,755
Service-based fee income	2,150		2,027
(Losses) gains on revaluation of foreign currency instruments	-20,159	[1]	978	[1]
Other	5,207	[2]	5,440	[2]
Total other noninterest (loss) income	($9,080)		$11,200
[1]	Represents the revaluation of foreign currency denominated financial instruments issued and held by us, primarily loans, deposits and cash.
[2]	Includes dividends on FHLB/FRB stock, correspondent bank rebate income and other fee income.

Other_Noninterest_Loss_Income_3

Other Noninterest (Loss) Income and Other Noninterest Expense - Summary of Other Noninterest Expense (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Other Income and Expenses [Abstract]
Client services	$3,549	$2,359
Telephone	1,959	1,748
Data processing services	1,833	2,227
Postage and supplies	765	769
Dues and publications	585	497
Other	4,907	1,562
Total other noninterest expense	$13,598	$9,162	[1]
[1]	Prior period amounts have been revised to reflect the retrospective application of new accounting guidance adopted in the first quarter of 2015 related to our investments in qualified affordable housing projects (ASU 2014-01). See Note 1 - "Basis of Presentation" of the "Notes to Interim Consolidated Financial Statements" under Part I, Item 1 in this report.

Segment_Reporting_Additional_I

Segment Reporting - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2015
	Segment
Segment Reporting [Abstract]
Number of reportable segments	3

Segment_Reporting_Segment_Info

Segment Reporting - Segment Information (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015		Mar. 31, 2014
Segment Reporting Information [Line Items]
Net interest income	$238,890		$196,328
(Provision for) reduction of loan losses	-6,452		-494
Noninterest income	172,018		310,225
Noninterest expense	-196,108	[1]	-170,408	[1],[2]
Income before income tax expense	208,348	[3]	335,651	[2],[3]
Total average loans, net of unearned income	14,046,369		10,767,684
Total average assets	39,300,589	[4]	27,767,633	[4]
Total average deposits	33,857,779		23,676,448
Global Commercial Bank
Segment Reporting Information [Line Items]
Net interest income	203,755	[5]	175,303	[5]
(Provision for) reduction of loan losses	-6,460	[5]	-807	[5]
Noninterest income	64,689	[5]	58,635	[5]
Noninterest expense	-136,282	[1],[5]	-120,706	[1],[5]
Income before income tax expense	125,702	[3],[5]	112,425	[3],[5]
Total average loans, net of unearned income	12,729,630	[5]	9,677,957	[5]
Total average assets	35,962,427	[4],[5]	25,504,407	[4],[5]
Total average deposits	32,472,827	[5]	22,877,819	[5]
SVB Private Bank
Segment Reporting Information [Line Items]
Net interest income	9,723		6,892
(Provision for) reduction of loan losses	8		313
Noninterest income	397		274
Noninterest expense	-2,747	[1]	-2,495	[1]
Income before income tax expense	7,381	[3]	4,984	[3]
Total average loans, net of unearned income	1,374,189		1,049,901
Total average assets	1,921,554	[4]	967,873	[4]
Total average deposits	1,251,939		745,083
SVB Capital
Segment Reporting Information [Line Items]
Net interest income	-24	[5]	14	[5]
(Provision for) reduction of loan losses	0	[5]	0	[5]
Noninterest income	21,141	[5]	37,672	[5]
Noninterest expense	-3,891	[1],[5]	-2,635	[1],[5]
Income before income tax expense	17,226	[3],[5]	35,051	[3],[5]
Total average loans, net of unearned income	0	[5]	0	[5]
Total average assets	269,982	[4],[5]	340,990	[4],[5]
Total average deposits	0	[5]	0	[5]
Other Items
Segment Reporting Information [Line Items]
Net interest income	25,436	[6]	14,119	[6]
(Provision for) reduction of loan losses	0	[6]	0	[6]
Noninterest income	85,791	[6]	213,644	[6]
Noninterest expense	-53,188	[1],[6]	-44,572	[1],[6]
Income before income tax expense	58,039	[3],[6]	183,191	[3],[6]
Total average loans, net of unearned income	-57,450	[6]	39,826	[6]
Total average assets	1,146,626	[4],[6]	954,363	[4],[6]
Total average deposits	$133,013	[6]	$53,546	[6]
[1]	The Global Commercial Bank segment includes direct depreciation and amortization of $5.1 million and $4.9 million for the three months ended March 31, 2015 and 2014, respectively
[2]	Prior period amounts have been revised to reflect the retrospective application of new accounting guidance adopted in the first quarter of 2015 related to our investments in qualified affordable housing projects (ASU 2014-01). See Note 1 - "Basis of Presentation" of the "Notes to Interim Consolidated Financial Statements" under Part I, Item 1 in this report.
[3]	The internal reporting model used by management to assess segment performance does not calculate income tax expense by segment. Our effective tax rate is a reasonable approximation of the segment rates.
[4]	Total average assets equal the greater of total average assets or the sum of total liabilities and total stockholders’ equity for each segment.
[5]	Global Commercial Bank’s and SVB Capital’s components of net interest income, noninterest income, noninterest expense and total average assets are shown net of noncontrolling interests for all periods presented. Noncontrolling interest is included within "Other Items".
[6]	The "Other Items" column reflects the adjustments necessary to reconcile the results of the operating segments to the consolidated financial statements prepared in conformity with GAAP. Noninterest income is primarily attributable to noncontrolling interests and gains on equity warrant assets. Noninterest expense primarily consists of expenses associated with corporate support functions such as finance, human resources, marketing, legal and other expenses. Additionally, average assets primarily consist of cash and cash equivalents and loans from our Community Development Finance practice as part of our responsibilities under the Community Reinvestment Act.

Segment_Reporting_Segment_Info1

Segment Reporting - Segment Information (Additional Information) (Detail) (Global Commercial Bank, USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Global Commercial Bank
Segment Reporting Information [Line Items]
Depreciation and amortization	$5.10	$4.90

OffBalance_Sheet_Arrangements_2

Off-Balance Sheet Arrangements, Guarantees and Other Commitments - Summary Information Related to Commitments to Extend Credit (Excluding Letters of Credit) (Detail) (USD $)	Mar. 31, 2015		Dec. 31, 2014
In Thousands, unless otherwise specified
Disclosure Off Balance Sheet Arrangements Guarantees And Other Commitments Additional Information [Abstract]
Fixed interest rate commitments	$1,611,025	[1]	$1,591,408	[1]
Variable interest rate commitments	12,618,196	[1]	11,860,039	[1]
Total loan commitments available for funding	14,229,221	[1]	13,451,447	[1]
Commercial and standby letters of credit	1,256,293	[2]	1,254,338	[2]
Total unfunded credit commitments	15,485,514		14,705,785
Commitments unavailable for funding	1,920,937	[3]	1,868,489	[3]
Maximum lending limits for accounts receivable factoring arrangements	1,120,763	[4]	1,044,548	[4]
Reserve for unfunded credit commitments	$38,628	[5]	$36,419	[5]
[1]	Represents commitments which are available for funding, due to clients meeting all collateral, compliance and financial covenants required under loan commitment agreements.
[2]	See below for additional information on our commercial and standby letters of credit.
[3]	Represents commitments which are currently unavailable for funding, due to clients failing to meet all collateral, compliance and financial covenants under loan commitment agreements.
[4]	We extend credit under accounts receivable factoring arrangements when our clients’ sales invoices are deemed creditworthy under existing underwriting practices.
[5]	Our reserve for unfunded credit commitments includes an allowance for both our unfunded loan commitments and our letters of credit.

OffBalance_Sheet_Arrangements_3

Off-Balance Sheet Arrangements, Guarantees and Other Commitments - Summary of Commercial and Standby Letters of Credit (Detail) (USD $)	Mar. 31, 2015		Dec. 31, 2014
In Thousands, unless otherwise specified
Guarantor Obligations [Line Items]
Expires In One Year or Less	$1,191,746
Expires After One Year	64,547
Total Amount Outstanding	1,256,293	[1]	1,254,338	[1]
Maximum Amount of Future Payments	1,256,293
Financial standby letters of credit
Guarantor Obligations [Line Items]
Expires In One Year or Less	1,137,234
Expires After One Year	57,997
Total Amount Outstanding	1,195,231
Maximum Amount of Future Payments	1,195,231
Performance standby letters of credit
Guarantor Obligations [Line Items]
Expires In One Year or Less	45,105
Expires After One Year	6,550
Total Amount Outstanding	51,655
Maximum Amount of Future Payments	51,655
Commercial letters of credit
Guarantor Obligations [Line Items]
Expires In One Year or Less	9,407
Expires After One Year	0
Total Amount Outstanding	9,407
Maximum Amount of Future Payments	$9,407
[1]	See below for additional information on our commercial and standby letters of credit.

OffBalance_Sheet_Arrangements_4

Off-Balance Sheet Arrangements, Guarantees and Other Commitments - Additional Information (Detail) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015
Venture capital and private equity fund investments
Commitments and Contingencies Disclosure [Line Items]
Commitments to invest, period from the inception of the fund	10 years
Call unrestricted, percentage of committed capital	100.00%
Venture capital and private equity fund investments | Lower Limit
Commitments and Contingencies Disclosure [Line Items]
Expected commitment period to invest in venture capital and private equity funds (in years)	5 years
Venture capital and private equity fund investments | Upper Limit
Commitments and Contingencies Disclosure [Line Items]
Expected commitment period to invest in venture capital and private equity funds (in years)	7 years
Standby Letter of Credit
Commitments and Contingencies Disclosure [Line Items]
Deferred fees	8.2
Collateral in the form of cash	509
Collateral in the form of investment securities	1.5

OffBalance_Sheet_Arrangements_5

Off-Balance Sheet Arrangements, Guarantees and Other Commitments - Total Capital Commitments, Unfunded Capital Commitments, and Our Ownership in Each Fund (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015
Venture Capital and Private Equity Fund Investments [Line Items]
SVBFG Unfunded Commitments	$557,992
SVB Strategic Investors Fund, LP
Venture Capital and Private Equity Fund Investments [Line Items]
SVBFG Unfunded Commitments	2,250
SVB Strategic Investors Fund II, LP
Venture Capital and Private Equity Fund Investments [Line Items]
SVBFG Unfunded Commitments	5,021
SVB Strategic Investors Fund III, LP
Venture Capital and Private Equity Fund Investments [Line Items]
SVBFG Unfunded Commitments	11,237
SVB Strategic Investors Fund IV, LP
Venture Capital and Private Equity Fund Investments [Line Items]
SVBFG Unfunded Commitments	32,730
Strategic Investors Fund V Funds
Venture Capital and Private Equity Fund Investments [Line Items]
SVBFG Unfunded Commitments	123,888
Strategic Investors Fund VI Funds
Venture Capital and Private Equity Fund Investments [Line Items]
SVBFG Unfunded Commitments	219,750
SVB Capital Preferred Return Fund, LP
Venture Capital and Private Equity Fund Investments [Line Items]
SVBFG Unfunded Commitments	4,448
SVB Capital—NT Growth Partners, LP
Venture Capital and Private Equity Fund Investments [Line Items]
SVBFG Unfunded Commitments	4,672
Other private equity fund
Venture Capital and Private Equity Fund Investments [Line Items]
SVBFG Unfunded Commitments	77
Parent Company
Venture Capital and Private Equity Fund Investments [Line Items]
SVBFG Capital Commitments	502,191
SVBFG Unfunded Commitments	41,256
Parent Company | Silicon Valley BancVentures, LP
Venture Capital and Private Equity Fund Investments [Line Items]
SVBFG Capital Commitments	6,000
SVBFG Unfunded Commitments	270
SVBFG Ownership of each Fund	10.70%	[1]
Parent Company | SVB Capital Partners II, LP
Venture Capital and Private Equity Fund Investments [Line Items]
SVBFG Capital Commitments	1,200	[2]
SVBFG Unfunded Commitments	162	[2]
SVBFG Ownership of each Fund	5.10%	[1],[2]
Parent Company | Capital Partners III, LP
Venture Capital and Private Equity Fund Investments [Line Items]
SVBFG Capital Commitments	0
SVBFG Unfunded Commitments	0
SVBFG Ownership of each Fund	0.00%	[1]
Parent Company | SVB Capital Shanghai Yangpu Venture Capital Fund
Venture Capital and Private Equity Fund Investments [Line Items]
SVBFG Capital Commitments	935
SVBFG Unfunded Commitments	0
SVBFG Ownership of each Fund	6.80%	[1]
Parent Company | SVB Strategic Investors Fund, LP
Venture Capital and Private Equity Fund Investments [Line Items]
SVBFG Capital Commitments	15,300
SVBFG Unfunded Commitments	688
SVBFG Ownership of each Fund	12.60%	[1]
Parent Company | SVB Strategic Investors Fund II, LP
Venture Capital and Private Equity Fund Investments [Line Items]
SVBFG Capital Commitments	15,000
SVBFG Unfunded Commitments	1,050
SVBFG Ownership of each Fund	8.60%	[1]
Parent Company | SVB Strategic Investors Fund III, LP
Venture Capital and Private Equity Fund Investments [Line Items]
SVBFG Capital Commitments	15,000
SVBFG Unfunded Commitments	1,275
SVBFG Ownership of each Fund	5.90%	[1]
Parent Company | SVB Strategic Investors Fund IV, LP
Venture Capital and Private Equity Fund Investments [Line Items]
SVBFG Capital Commitments	12,239
SVBFG Unfunded Commitments	2,325
SVBFG Ownership of each Fund	5.00%	[1]
Parent Company | Strategic Investors Fund V Funds
Venture Capital and Private Equity Fund Investments [Line Items]
SVBFG Capital Commitments	515
SVBFG Unfunded Commitments	178
Parent Company | Strategic Investors Fund VI Funds
Venture Capital and Private Equity Fund Investments [Line Items]
SVBFG Capital Commitments	0
SVBFG Unfunded Commitments	0
SVBFG Ownership of each Fund	0.00%	[1]
Parent Company | Strategic Investors Fund VII Funds
Venture Capital and Private Equity Fund Investments [Line Items]
SVBFG Capital Commitments	0
SVBFG Unfunded Commitments	0
SVBFG Ownership of each Fund	0.00%	[1]
Parent Company | SVB Capital Preferred Return Fund, LP
Venture Capital and Private Equity Fund Investments [Line Items]
SVBFG Capital Commitments	12,688
SVBFG Unfunded Commitments	0
SVBFG Ownership of each Fund	20.00%	[1]
Parent Company | SVB Capital—NT Growth Partners, LP
Venture Capital and Private Equity Fund Investments [Line Items]
SVBFG Capital Commitments	24,670
SVBFG Unfunded Commitments	1,340
SVBFG Ownership of each Fund	33.00%	[1]
Parent Company | Other private equity fund
Venture Capital and Private Equity Fund Investments [Line Items]
SVBFG Capital Commitments	9,338	[3]
SVBFG Unfunded Commitments	0	[3]
SVBFG Ownership of each Fund	58.20%	[1],[3]
Parent Company | Partners for Growth, LP
Venture Capital and Private Equity Fund Investments [Line Items]
SVBFG Capital Commitments	25,000
SVBFG Unfunded Commitments	9,750
SVBFG Ownership of each Fund	50.00%	[1]
Parent Company | Debt funds (equity method accounting)
Venture Capital and Private Equity Fund Investments [Line Items]
SVBFG Capital Commitments	63,134
SVBFG Unfunded Commitments	4,950
Parent Company | Other fund investments
Venture Capital and Private Equity Fund Investments [Line Items]
SVBFG Capital Commitments	301,172	[4]
SVBFG Unfunded Commitments	$19,268	[4]
[1]	We are subject to the Volcker Rule, which restricts or limits us from sponsoring or having ownership interests in “covered” funds including venture capital and private equity funds. See “Business - Supervision and Regulation” under Item 1 of Part I of our 2014 Form 10-K.
[2]	Our ownership includes direct ownership of 1.3 percent and indirect ownership interest of 3.8 percent through our investment in SVB Strategic Investors Fund II, LP.
[3]	Our ownership includes direct ownership of 41.5 percent and indirect ownership interests of 12.6 percent and 4.1 percent in the fund through our ownership interest of SVB Capital - NT Growth Partners, LP and SVB Capital Preferred Return Fund, LP, respectively.
[4]	Represents commitments to 283 funds (primarily venture capital funds) where our ownership interest is generally less than 5 percent of the voting interests of each such fund.

OffBalance_Sheet_Arrangements_6

Off-Balance Sheet Arrangements, Guarantees and Other Commitments - Total Capital Commitments, Unfunded Capital Commitments, and Our Ownership in Each Fund (Additional Information) (Detail) (Venture capital and private equity fund investments)	3 Months Ended		12 Months Ended
	Mar. 31, 2015		Dec. 31, 2014
SVB Capital Partners II, LP | Fair value accounting
Venture Capital and Private Equity Fund Investments [Line Items]
Percentage of ownership	5.10%	[1]	5.10%	[1]
SVB Capital Partners II, LP | Fair value accounting | Direct ownership interest
Venture Capital and Private Equity Fund Investments [Line Items]
Percentage of ownership	1.30%
SVB Capital Partners II, LP | Fair value accounting | Indirect ownership interest
Venture Capital and Private Equity Fund Investments [Line Items]
Percentage of ownership	3.80%
Other private equity fund | Fair value accounting
Venture Capital and Private Equity Fund Investments [Line Items]
Percentage of ownership	58.20%	[2]	58.20%	[2]
Other private equity fund | Fair value accounting | Direct ownership interest
Venture Capital and Private Equity Fund Investments [Line Items]
Percentage of ownership	41.50%
Other fund investments
Venture Capital and Private Equity Fund Investments [Line Items]
Number of other funds with investment commitments	283
Upper Limit | Other fund investments
Venture Capital and Private Equity Fund Investments [Line Items]
Percentage of ownership	5.00%
SVB Capital—NT Growth Partners, LP | Other private equity fund | Fair value accounting | Indirect ownership interest
Venture Capital and Private Equity Fund Investments [Line Items]
Percentage of ownership	12.60%
SVB Capital Preferred Return Fund, LP | Other private equity fund | Fair value accounting | Indirect ownership interest
Venture Capital and Private Equity Fund Investments [Line Items]
Percentage of ownership	4.10%
[1]	At March 31, 2015, we had a direct ownership interest of 1.3 percent and an indirect ownership interest of 3.8 percent in the fund through our ownership interest of SVB Strategic Investors Fund II, LP.
[2]	At March 31, 2015, we had a direct ownership interest of 41.5 percent and indirect ownership interests of 12.6 percent and 4.1 percent in the fund through our ownership interest of SVB Capital—NT Growth Partners, LP and SVB Capital Preferred Return Fund, LP, respectively.

OffBalance_Sheet_Arrangements_7

Off-Balance Sheet Arrangements, Guarantees and Other Commitments - Remaining Unfunded Commitments to Venture Capital or Private Equity Funds by our Consolidated Managed Funds (Detail) (USD $)	Mar. 31, 2015
In Thousands, unless otherwise specified
Commitments and Contingencies Disclosure [Line Items]
SVBFG Unfunded Commitments	$557,992
SVB Strategic Investors Fund, LP
Commitments and Contingencies Disclosure [Line Items]
SVBFG Unfunded Commitments	2,250
SVB Strategic Investors Fund II, LP
Commitments and Contingencies Disclosure [Line Items]
SVBFG Unfunded Commitments	5,021
SVB Strategic Investors Fund III, LP
Commitments and Contingencies Disclosure [Line Items]
SVBFG Unfunded Commitments	11,237
SVB Strategic Investors Fund IV, LP
Commitments and Contingencies Disclosure [Line Items]
SVBFG Unfunded Commitments	32,730
Strategic Investors Fund V Funds
Commitments and Contingencies Disclosure [Line Items]
SVBFG Unfunded Commitments	123,888
Strategic Investors Fund VI Funds
Commitments and Contingencies Disclosure [Line Items]
SVBFG Unfunded Commitments	219,750
Strategic Investors Fund VII Funds [Domain]
Commitments and Contingencies Disclosure [Line Items]
SVBFG Unfunded Commitments	153,919
SVB Capital Preferred Return Fund, LP
Commitments and Contingencies Disclosure [Line Items]
SVBFG Unfunded Commitments	4,448
SVB Capital—NT Growth Partners, LP
Commitments and Contingencies Disclosure [Line Items]
SVBFG Unfunded Commitments	4,672
Other private equity fund
Commitments and Contingencies Disclosure [Line Items]
SVBFG Unfunded Commitments	$77

Income_Taxes_Detail

Income Taxes (Detail) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015
Income Tax Examination [Line Items]
Unrecognized tax benefit	3.8
Reduction in income tax expense resulting from recognition of unrecognized tax benefit	2.7
Federal tax
Income Tax Examination [Line Items]
Tax years open to examination	Our U.S. federal tax returns for 2011 and subsequent years remain open to full examination
State tax
Income Tax Examination [Line Items]
Tax years open to examination	Our California tax returns for 2010 and subsequent tax years remain open to full examination. Massachusetts tax returns for 2011 and subsequent years remain open to full examination

Fair_Value_of_Financial_Instru2

Fair Value of Financial Instruments - Assets and Liabilities Measured at Fair Value on a Recurring Basis (Detail) (USD $)	Mar. 31, 2015		Dec. 31, 2014
In Thousands, unless otherwise specified
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying Value	$13,746,923		$13,540,655
Derivatives designated as hedging instruments | Interest rate risks | Interest rate swaps | Other assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Assets	4,340		4,609
Derivatives not designated as hedging instruments | Other derivative instruments | Equity warrant asset | Other assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Assets	124,456		116,604
Fair value accounting
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Non-marketable securities	11,936	[1]	108,251	[1]
Fair value accounting | Venture capital and private equity fund investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Non-marketable securities	1,195,303	[2]	1,130,882	[2]
Fair value accounting | Other venture capital investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Non-marketable securities	78,850	[3]	71,204	[3]
U.S. treasury securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying Value	7,914,125		7,302,273
U.S. agency debentures
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying Value	3,313,664		3,561,556
Residential mortgage-backed securities | Agency-issued collateralized mortgage obligations | Fixed rate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying Value	1,778,155		1,884,843
Residential mortgage-backed securities | Agency-issued collateralized mortgage obligations | Variable rate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying Value	739,203		784,475
Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying Value	1,776		7,508
Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying Value	13,746,923		13,540,655
Total assets	15,219,210	[4]	15,008,982	[5]
Total liabilities	48,893		31,111
Fair Value, Measurements, Recurring | Derivatives designated as hedging instruments | Interest rate risks | Interest rate swaps | Other assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Assets	4,340		4,609
Fair Value, Measurements, Recurring | Derivatives not designated as hedging instruments | Currency exchange risks | Other assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Assets	54,495		34,231
Fair Value, Measurements, Recurring | Derivatives not designated as hedging instruments | Currency exchange risks | Other liability
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, Liabilities	45,727		28,363
Fair Value, Measurements, Recurring | Derivatives not designated as hedging instruments | Other derivative instruments | Equity warrant asset | Other assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Assets	124,456		116,604
Fair Value, Measurements, Recurring | Derivatives not designated as hedging instruments | Other derivative instruments | Client interest rate derivatives | Other assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Assets	2,907		2,546
Fair Value, Measurements, Recurring | Derivatives not designated as hedging instruments | Other derivative instruments | Client interest rate derivatives | Other liability
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, Liabilities	3,166		2,748
Fair Value, Measurements, Recurring | Fair value accounting
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Non-marketable securities	1,286,089		1,310,337
Fair Value, Measurements, Recurring | Fair value accounting | Venture capital and private equity fund investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Non-marketable securities	1,195,303		1,130,882
Fair Value, Measurements, Recurring | Fair value accounting | Other venture capital investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Non-marketable securities	78,850		71,204
Fair Value, Measurements, Recurring | Fair value accounting | Other securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Non-marketable securities	11,936		108,251
Fair Value, Measurements, Recurring | U.S. treasury securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying Value	7,914,125		7,302,273
Fair Value, Measurements, Recurring | U.S. agency debentures
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying Value	3,313,664		3,561,556
Fair Value, Measurements, Recurring | Residential mortgage-backed securities | Agency-issued collateralized mortgage obligations | Fixed rate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying Value	1,778,155		1,884,843
Fair Value, Measurements, Recurring | Residential mortgage-backed securities | Agency-issued collateralized mortgage obligations | Variable rate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying Value	739,203		784,475
Fair Value, Measurements, Recurring | Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying Value	1,776		7,508
Fair Value, Measurements, Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying Value	7,915,507		7,306,563
Total assets	7,927,443	[4]	7,414,814	[5]
Total liabilities	0		0
Fair Value, Measurements, Recurring | Level 1 | Derivatives designated as hedging instruments | Interest rate risks | Interest rate swaps | Other assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Assets	0		0
Fair Value, Measurements, Recurring | Level 1 | Derivatives not designated as hedging instruments | Currency exchange risks | Other assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Assets	0		0
Fair Value, Measurements, Recurring | Level 1 | Derivatives not designated as hedging instruments | Currency exchange risks | Other liability
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, Liabilities	0		0
Fair Value, Measurements, Recurring | Level 1 | Derivatives not designated as hedging instruments | Other derivative instruments | Equity warrant asset | Other assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Assets	0		0
Fair Value, Measurements, Recurring | Level 1 | Derivatives not designated as hedging instruments | Other derivative instruments | Client interest rate derivatives | Other assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Assets	0		0
Fair Value, Measurements, Recurring | Level 1 | Derivatives not designated as hedging instruments | Other derivative instruments | Client interest rate derivatives | Other liability
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, Liabilities	0		0
Fair Value, Measurements, Recurring | Level 1 | Fair value accounting
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Non-marketable securities	11,936		108,251
Fair Value, Measurements, Recurring | Level 1 | Fair value accounting | Venture capital and private equity fund investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Non-marketable securities	0		0
Fair Value, Measurements, Recurring | Level 1 | Fair value accounting | Other venture capital investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Non-marketable securities	0		0
Fair Value, Measurements, Recurring | Level 1 | Fair value accounting | Other securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Non-marketable securities	11,936		108,251
Fair Value, Measurements, Recurring | Level 1 | U.S. treasury securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying Value	7,914,125		7,302,273
Fair Value, Measurements, Recurring | Level 1 | U.S. agency debentures
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying Value	0		0
Fair Value, Measurements, Recurring | Level 1 | Residential mortgage-backed securities | Agency-issued collateralized mortgage obligations | Fixed rate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying Value	0		0
Fair Value, Measurements, Recurring | Level 1 | Residential mortgage-backed securities | Agency-issued collateralized mortgage obligations | Variable rate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying Value	0		0
Fair Value, Measurements, Recurring | Level 1 | Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying Value	1,382		4,290
Fair Value, Measurements, Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying Value	5,831,416		6,234,092
Total assets	5,895,353	[4]	6,277,384	[5]
Total liabilities	48,893		31,111
Fair Value, Measurements, Recurring | Level 2 | Derivatives designated as hedging instruments | Interest rate risks | Interest rate swaps | Other assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Assets	4,340		4,609
Fair Value, Measurements, Recurring | Level 2 | Derivatives not designated as hedging instruments | Currency exchange risks | Other assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Assets	54,495		34,231
Fair Value, Measurements, Recurring | Level 2 | Derivatives not designated as hedging instruments | Currency exchange risks | Other liability
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, Liabilities	45,727		28,363
Fair Value, Measurements, Recurring | Level 2 | Derivatives not designated as hedging instruments | Other derivative instruments | Equity warrant asset | Other assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Assets	2,195		1,906
Fair Value, Measurements, Recurring | Level 2 | Derivatives not designated as hedging instruments | Other derivative instruments | Client interest rate derivatives | Other assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Assets	2,907		2,546
Fair Value, Measurements, Recurring | Level 2 | Derivatives not designated as hedging instruments | Other derivative instruments | Client interest rate derivatives | Other liability
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, Liabilities	3,166		2,748
Fair Value, Measurements, Recurring | Level 2 | Fair value accounting
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Non-marketable securities	0		0
Fair Value, Measurements, Recurring | Level 2 | Fair value accounting | Venture capital and private equity fund investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Non-marketable securities	0		0
Fair Value, Measurements, Recurring | Level 2 | Fair value accounting | Other venture capital investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Non-marketable securities	0		0
Fair Value, Measurements, Recurring | Level 2 | Fair value accounting | Other securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Non-marketable securities	0		0
Fair Value, Measurements, Recurring | Level 2 | U.S. treasury securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying Value	0		0
Fair Value, Measurements, Recurring | Level 2 | U.S. agency debentures
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying Value	3,313,664		3,561,556
Fair Value, Measurements, Recurring | Level 2 | Residential mortgage-backed securities | Agency-issued collateralized mortgage obligations | Fixed rate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying Value	1,778,155		1,884,843
Fair Value, Measurements, Recurring | Level 2 | Residential mortgage-backed securities | Agency-issued collateralized mortgage obligations | Variable rate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying Value	739,203		784,475
Fair Value, Measurements, Recurring | Level 2 | Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying Value	394		3,218
Fair Value, Measurements, Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying Value	0		0
Total assets	1,396,414	[4]	1,316,784	[5]
Total liabilities	0		0
Fair Value, Measurements, Recurring | Level 3 | Derivatives designated as hedging instruments | Interest rate risks | Interest rate swaps | Other assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Assets	0		0
Fair Value, Measurements, Recurring | Level 3 | Derivatives not designated as hedging instruments | Currency exchange risks | Other assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Assets	0		0
Fair Value, Measurements, Recurring | Level 3 | Derivatives not designated as hedging instruments | Currency exchange risks | Other liability
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, Liabilities	0		0
Fair Value, Measurements, Recurring | Level 3 | Derivatives not designated as hedging instruments | Other derivative instruments | Equity warrant asset | Other assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Assets	122,261		114,698
Fair Value, Measurements, Recurring | Level 3 | Derivatives not designated as hedging instruments | Other derivative instruments | Client interest rate derivatives | Other assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Assets	0		0
Fair Value, Measurements, Recurring | Level 3 | Derivatives not designated as hedging instruments | Other derivative instruments | Client interest rate derivatives | Other liability
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, Liabilities	0		0
Fair Value, Measurements, Recurring | Level 3 | Fair value accounting
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Non-marketable securities	1,274,153		1,202,086
Fair Value, Measurements, Recurring | Level 3 | Fair value accounting | Venture capital and private equity fund investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Non-marketable securities	1,195,303		1,130,882
Fair Value, Measurements, Recurring | Level 3 | Fair value accounting | Other venture capital investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Non-marketable securities	78,850		71,204
Fair Value, Measurements, Recurring | Level 3 | Fair value accounting | Other securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Non-marketable securities	0		0
Fair Value, Measurements, Recurring | Level 3 | U.S. treasury securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying Value	0		0
Fair Value, Measurements, Recurring | Level 3 | U.S. agency debentures
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying Value	0		0
Fair Value, Measurements, Recurring | Level 3 | Residential mortgage-backed securities | Agency-issued collateralized mortgage obligations | Fixed rate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying Value	0		0
Fair Value, Measurements, Recurring | Level 3 | Residential mortgage-backed securities | Agency-issued collateralized mortgage obligations | Variable rate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying Value	0		0
Fair Value, Measurements, Recurring | Level 3 | Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying Value	0		0
Noncontrolling Interests | Fair Value, Measurements, Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	9,100		100,000
Noncontrolling Interests | Fair Value, Measurements, Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	$1,200,000		$1,100,000
[1]	Investments classified as other securities (fair value accounting) represent direct equity investments in public companies held by our consolidated funds. At December 31, 2014, the amount primarily included total unrealized gains in one public company, FireEye, Inc. ("FireEye"). During the first quarter of 2015, our managed direct venture funds distributed the remaining 2.5 million shares of FireEye common stock to their respective investors (including the Company), resulting in $15.9 million of realized gains on investment securities ($3.3 million net of noncontrolling interests but inclusive of the Company's carried interests). As of March 31, 2015, we no longer hold any shares of FireEye common stock, either directly or through our managed direct venture funds.
[2]	The following table shows the amounts of venture capital and private equity fund investments held by the following consolidated funds and our ownership percentage of each fund at March 31, 2015 and December 31, 2014 (fair value accounting): March 31, 2015 December 31, 2014(Dollars in thousands) Amount Ownership % Amount Ownership %SVB Strategic Investors Fund, LP $23,953 12.6% $24,645 12.6%SVB Strategic Investors Fund II, LP 89,219 8.6 97,250 8.6SVB Strategic Investors Fund III, LP 257,539 5.9 269,821 5.9SVB Strategic Investors Fund IV, LP 297,752 5.0 291,291 5.0Strategic Investors Fund V Funds 260,292 Various 226,111 VariousStrategic Investors Fund VI Funds 127,721 — 89,605 —Strategic Investors Fund VII Funds 2,212 — — —SVB Capital Preferred Return Fund, LP 64,417 20.0 62,110 20.0SVB Capital—NT Growth Partners, LP 64,078 33.0 61,973 33.0SVB Capital Partners II, LP (i) 346 5.1 302 5.1Other private equity fund (ii) 7,774 58.2 7,774 58.2Total venture capital and private equity fund investments $1,195,303 $1,130,882 (i)At March 31, 2015, we had a direct ownership interest of 1.3 percent and an indirect ownership interest of 3.8 percent in the fund through our ownership interest of SVB Strategic Investors Fund II, LP.(ii)At March 31, 2015, we had a direct ownership interest of 41.5 percent and indirect ownership interests of 12.6 percent and 4.1 percent in the fund through our ownership interest of SVB Capital—NT Growth Partners, LP and SVB Capital Preferred Return Fund, LP, respectively.
[3]	The following table shows the amounts of other venture capital investments held by the following consolidated funds and our ownership percentage of each fund at March 31, 2015 and December 31, 2014 (fair value accounting): March 31, 2015 December 31, 2014(Dollars in thousands) Amount Ownership % Amount Ownership %Silicon Valley BancVentures, LP $3,390 10.7% $3,291 10.7%SVB Capital Partners II, LP (i) 27,215 5.1 20,481 5.1Capital Partners III, LP 41,055 — 41,055 —SVB Capital Shanghai Yangpu Venture Capital Fund 7,190 6.8 6,377 6.8Total other venture capital investments $78,850 $71,204 (i)At March 31, 2015, we had a direct ownership interest of 1.3 percent and an indirect ownership interest of 3.8 percent in the fund through our ownership of SVB Strategic Investors Fund II, LP.
[4]	Included in Level 1 and Level 3 assets are $9 million and $1.2 billion, respectively, attributable to noncontrolling interests calculated based on the ownership percentages of the noncontrolling interests.
[5]	Included in Level 1 and Level 3 assets are $100 million and $1.1 billion, respectively, attributable to noncontrolling interests calculated based on the ownership percentages of the noncontrolling interests.

Fair_Value_of_Financial_Instru3

Fair Value of Financial Instruments - Additional Information about Level 3 Assets Measured at Fair Value on a Recurring Basis (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015		Mar. 31, 2014
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	$1,316,784		$1,314,951
Total Realized and Unrealized Gains Included in Income	73,388		240,245
Purchases	60,040		45,125
Sales	-14,804		-90,347
Issuances	2,083		3,417
Distributions and Other Settlements	-40,834		-41,324
Transfers Out of Level 3	-243		-16,710
Ending Balance	1,396,414		1,455,357
Equity warrant assets | Other assets
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	114,698	[1]	99,891	[1]
Total Realized and Unrealized Gains Included in Income	20,084	[1]	24,378	[1]
Purchases	0	[1]	0	[1]
Sales	-14,765	[1]	-39,993	[1]
Issuances	2,083	[1]	3,417	[1]
Distributions and Other Settlements	404	[1]	626	[1]
Transfers Out of Level 3	-243	[1]	-677	[1]
Ending Balance	122,261	[1]	87,642	[1]
Non-marketable securities | Fair value accounting
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	1,202,086	[2]	1,215,060	[2]
Total Realized and Unrealized Gains Included in Income	53,304	[2]	215,867	[2]
Purchases	60,040	[2]	45,125	[2]
Sales	-39	[2]	-50,354	[2]
Issuances	0	[2]	0	[2]
Distributions and Other Settlements	-41,238	[2]	-41,950	[2]
Transfers Out of Level 3	0	[2]	-16,033	[2]
Ending Balance	1,274,153	[2]	1,367,715	[2]
Non-marketable securities | Fair value accounting | Venture capital and private equity fund investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	1,130,882		862,972
Total Realized and Unrealized Gains Included in Income	46,854		111,335
Purchases	58,670		44,455
Sales	0		0
Issuances	0		0
Distributions and Other Settlements	-41,103		-41,840
Transfers Out of Level 3	0		0
Ending Balance	1,195,303		976,922
Non-marketable securities | Fair value accounting | Other venture capital investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	71,204		32,839
Total Realized and Unrealized Gains Included in Income	6,450		1,838
Purchases	1,370		670
Sales	-39		-3,514
Issuances	0		0
Distributions and Other Settlements	-135		-3,527
Transfers Out of Level 3	0		0
Ending Balance	78,850		28,306
Non-marketable securities | Fair value accounting | Other investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance			319,249
Total Realized and Unrealized Gains Included in Income			102,694
Purchases			0
Sales			-46,840
Issuances			0
Distributions and Other Settlements			3,417
Transfers Out of Level 3			-16,033
Ending Balance			$362,487
[1]	Realized and unrealized gains (losses) are recorded in the line item “gains on derivative instruments, net”, a component of noninterest income.
[2]	Realized and unrealized gains (losses) are recorded in the line items “gains on investment securities, net”, and “other noninterest income”, components of noninterest income.

Fair_Value_of_Financial_Instru4

Fair Value of Financial Instruments - Unrealized Gains Included in Earnings Attributable to Level 3 Assets Held (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015		Mar. 31, 2014
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Unrealized Gains (Losses) [Line Items]
Unrealized gains included in earnings attributable to Level 3 assets still held	$68,575		$194,591
Unrealized gains attributable to noncontrolling interests	49,617		176,085
Equity warrant assets | Other assets
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Unrealized Gains (Losses) [Line Items]
Unrealized gains included in earnings attributable to Level 3 assets still held	16,261	[1]	3,782	[1]
Non-marketable securities | Fair value accounting
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Unrealized Gains (Losses) [Line Items]
Unrealized gains included in earnings attributable to Level 3 assets still held	52,314	[2]	190,809	[2]
Non-marketable securities | Fair value accounting | Venture capital and private equity fund investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Unrealized Gains (Losses) [Line Items]
Unrealized gains included in earnings attributable to Level 3 assets still held	45,935		111,856
Non-marketable securities | Fair value accounting | Other venture capital investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Unrealized Gains (Losses) [Line Items]
Unrealized gains included in earnings attributable to Level 3 assets still held	6,379		-15
Non-marketable securities | Fair value accounting | Other investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Unrealized Gains (Losses) [Line Items]
Unrealized gains included in earnings attributable to Level 3 assets still held	$0		$78,968
[1]	Unrealized gains (losses) are recorded in the line item “gains on derivative instruments, net”, a component of noninterest income.
[2]	Unrealized gains (losses) are recorded in the line items “gains on investment securities, net”, and “other noninterest income”, components of noninterest income.

Fair_Value_of_Financial_Instru5

Fair Value of Financial Instruments - Quantitative Information About Significant Unobservable Inputs (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015		Mar. 31, 2014		Dec. 31, 2014		Dec. 31, 2013
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair value	$1,396,414		1,455,357		$1,316,784		$1,314,951
Equity warrant assets | Other assets
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair value	122,261	[1]	87,642	[1]	114,698	[1]	99,891	[1]
Level 3 | Other venture capital investments | Fair value accounting
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair value	78,850				71,204
Valuation Technique	Private company equity pricing		Private company equity pricing
Level 3 | Equity warrant assets | Lower Limit
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Sales restrictions discount	10.00%
Level 3 | Equity warrant assets | Upper Limit
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Sales restrictions discount	20.00%
Level 3 | Equity warrant assets | Investments
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair value	1,472				1,681
Level 3 | Equity warrant assets | Other assets
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Valuation Technique	Modified Black-Scholes option pricing model		Modified Black-Scholes option pricing model
Volatility	46.60%		42.60%
Risk-Free interest rate	1.80%		1.70%
Sales restrictions discount	15.20%	[2]	17.80%	[2]
Level 3 | Equity Warrant Asset, Private Portfolio | Investments
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair value	$120,789				$113,017
Level 3 | Equity Warrant Asset, Private Portfolio | Other assets
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Valuation Technique	Modified Black-Scholes option pricing model		Modified Black-Scholes option pricing model
Volatility	38.10%		38.30%
Risk-Free interest rate	0.70%		0.90%
Marketability discount	18.10%	[3]	20.00%	[3]
Remaining life assumption	45.00%	[4]	45.00%	[4]
[1]	Realized and unrealized gains (losses) are recorded in the line item “gains on derivative instruments, net”, a component of noninterest income.
[2]	We adjust quoted market prices of public companies, which are subject to certain sales restrictions. Sales restriction discounts generally range from 10 percent to 20 percent depending on the duration of the sales restrictions, which typically range from 3 to 6 months.
[3]	Our marketability discount is applied to all private company warrants to account for a general lack of liquidity due to the private nature of the associated underlying company. The quantitative measure used is based upon various option-pricing models. On a quarterly basis, a sensitivity analysis is performed on our marketability discount.
[4]	We adjust the contractual remaining term of private company warrants based on our estimate of the actual remaining life, which we determine by utilizing historical data on cancellations and exercises. At March 31, 2015, the weighted average contractual remaining term was 2.61 years, compared to our estimated remaining life of 5.80 years. On a quarterly basis, a sensitivity analysis is performed on our remaining life assumption.

Fair_Value_of_Financial_Instru6

Fair Value of Financial Instruments - Quantitative Information About Significant Unobservable Inputs (Additional Information) (Detail) (Other assets, Equity warrant assets)	3 Months Ended
	Mar. 31, 2015
Other assets | Equity warrant assets
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Weighted average contractual remaining term	2 years 7 months 10 days
Estimated remaining life	5 years 9 months 18 days

Fair_Value_of_Financial_Instru7

Fair Value of Financial Instruments - Additional Information (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015		Mar. 31, 2014
Debt Disclosure [Line Items]
Investments transferred out of Level 3	$243		$16,710
Fair value accounting | Non-marketable securities
Debt Disclosure [Line Items]
Investments transferred out of Level 3	$0	[1]	$16,033	[1]
[1]	Realized and unrealized gains (losses) are recorded in the line items “gains on investment securities, net”, and “other noninterest income”, components of noninterest income.

Fair_Value_of_Financial_Instru8

Fair Value of Financial Instruments - Summary of Estimated Fair Values of Financial Instruments not Carried at Fair Value (Detail) (USD $)	Mar. 31, 2015		Dec. 31, 2014
In Thousands, unless otherwise specified
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity securities	$7,869,653		$7,415,656
Federal Home Loan Bank Advances	60,000		0
Short-term borrowings	77,766		7,781
Other short-term borrowings
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term borrowings	17,766	[1]	7,781	[1]
Senior Notes Three Point Five Zero Percent Due January Twenty Twenty Five [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes	349,710		0
5.375% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes	348,495		348,436
6.05% Subordinated Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Subordinated Notes	49,910	[2]	50,162	[2]
7.0% Junior Subordinated Debentures
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Junior Subordinated Debentures	54,802		54,845
Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	1,308,003		1,796,062
Held-to-maturity securities	7,816,797		7,421,042
Non-marketable securities (cost and equity method accounting)	295,427		296,648
Net commercial loans	12,900,215		12,947,869
Net consumer loans	1,371,484		1,271,048
Assets Held-for-sale, Long Lived, Fair Value Disclosure	48,200		44,253
FHLB and Federal Reserve Bank stock	53,496		53,496
Accrued interest receivable	91,415		94,180
Non-maturity deposits	33,752,797	[3]	34,215,372	[3]
Time deposits	98,778		128,127
Accrued interest payable	5,038		6,998
Commitments to extend credit	0		0
Carrying Amount | Other short-term borrowings
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term borrowings	17,766		7,781
Carrying Amount | Senior Notes Three Point Five Zero Percent Due January Twenty Twenty Five [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes	349,710
Carrying Amount | 5.375% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes	348,495		348,436
Carrying Amount | 6.05% Subordinated Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Subordinated Notes	49,910	[4]	50,162	[4]
Carrying Amount | 7.0% Junior Subordinated Debentures
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Junior Subordinated Debentures	54,802		54,845
Estimated Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets Held-for-sale, Long Lived, Fair Value Disclosure			45,410
Estimated Fair Value | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	1,308,003		1,796,062
Held-to-maturity securities	0		0
Non-marketable securities (cost and equity method accounting)	0		0
Net commercial loans	0		0
Net consumer loans	0		0
FHLB and Federal Reserve Bank stock	0		0
Accrued interest receivable	0		0
Federal Home Loan Bank Advances	60,000
Non-maturity deposits	33,752,797	[3]	34,215,372	[3]
Time deposits	0		0
Senior Notes	0
Accrued interest payable	0		0
Commitments to extend credit	0		0
Estimated Fair Value | Level 1 | Other short-term borrowings
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term borrowings	17,766		7,781
Estimated Fair Value | Level 1 | 5.375% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes	0		0
Estimated Fair Value | Level 1 | 6.05% Subordinated Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Subordinated Notes	0	[4]	0	[4]
Estimated Fair Value | Level 1 | 7.0% Junior Subordinated Debentures
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Junior Subordinated Debentures	0		0
Estimated Fair Value | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	0		0
Held-to-maturity securities	7,869,653		7,415,656
Non-marketable securities (cost and equity method accounting)	0		0
Net commercial loans	0		0
Net consumer loans	0		0
FHLB and Federal Reserve Bank stock	0		0
Accrued interest receivable	91,415		94,180
Federal Home Loan Bank Advances	0
Non-maturity deposits	0	[3]	0	[3]
Time deposits	98,740		128,107
Accrued interest payable	5,038		6,998
Commitments to extend credit	0		0
Estimated Fair Value | Level 2 | Other short-term borrowings
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term borrowings	0		0
Estimated Fair Value | Level 2 | Senior Notes Three Point Five Zero Percent Due January Twenty Twenty Five [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes	348,639
Estimated Fair Value | Level 2 | 5.375% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes	396,799		392,616
Estimated Fair Value | Level 2 | 6.05% Subordinated Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Subordinated Notes	52,963	[4]	53,537	[4]
Estimated Fair Value | Level 2 | 7.0% Junior Subordinated Debentures
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Junior Subordinated Debentures	53,109		52,990
Estimated Fair Value | Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	0		0
Held-to-maturity securities	0		0
Non-marketable securities (cost and equity method accounting)	402,301		390,570
Net commercial loans	13,034,516		13,082,487
Net consumer loans	1,347,284		1,247,336
FHLB and Federal Reserve Bank stock	53,496		53,496
Accrued interest receivable	0		0
Federal Home Loan Bank Advances	0
Non-maturity deposits	0	[3]	0	[3]
Time deposits	0		0
Senior Notes	0
Accrued interest payable	0		0
Commitments to extend credit	30,135		29,097
Estimated Fair Value | Level 3 | Other short-term borrowings
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term borrowings	0		0
Estimated Fair Value | Level 3 | 5.375% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes	0		0
Estimated Fair Value | Level 3 | 6.05% Subordinated Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Subordinated Notes	0	[4]	0	[4]
Estimated Fair Value | Level 3 | 7.0% Junior Subordinated Debentures
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Junior Subordinated Debentures	$0		$0
[1]	Represents cash collateral received from certain counterparties in relation to market value exposures of derivative contracts in our favor, which includes an interest rate swap agreement related to our 6.05% Subordinated Notes.
[2]	At March 31, 2015 and December 31, 2014, included in the carrying value of our 6.05% Subordinated Notes was an interest rate swap valued at $4.3 million and $4.6 million, respectively, related to hedge accounting associated with the notes.
[3]	Includes noninterest-bearing demand deposits, interest-bearing checking accounts, money market accounts and interest-bearing sweep deposits.
[4]	At March 31, 2015 and December 31, 2014, included in the carrying value and estimated fair value of our 6.05% Subordinated Notes was an interest rate swap valued at $4.3 million and $4.6 million, respectively, related to hedge accounting associated with the notes.

Fair_Value_of_Financial_Instru9

Fair Value of Financial Instruments - Summary of Estimated Fair Values of Financial Instruments not Carried at Fair Value (Additional Information) (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
5.375% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	5.38%	5.38%
6.05% Subordinated Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	6.05%	6.05%
Fair value of the interest rate swap associated with the notes	4,300	4,600
7.0% Junior Subordinated Debentures
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	7.00%	7.00%

Recovered_Sheet5

Fair Value of Financial Instruments - Summary of Estimated Fair Values of Investments and Remaining Unfunded Commitments for Each Major Category of Investments (Detail) (USD $)	Mar. 31, 2015
In Thousands, unless otherwise specified
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Carrying Amount	$1,380,010
Fair Value	1,484,919
Unfunded Commitments	579,813
Non-marketable securities | Fair value accounting | Venture capital and private equity fund investments
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Carrying Amount	1,195,303	[1]
Fair Value	1,195,303	[1]
Unfunded Commitments	557,992	[1]
Non-marketable securities | Equity method accounting | Other investments
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Carrying Amount	50,132	[2]
Fair Value	51,323	[2]
Unfunded Commitments	5,836	[2]
Non-marketable securities | Cost method accounting | Venture capital and private equity fund investments
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Carrying Amount	134,575	[3]
Fair Value	238,293	[3]
Unfunded Commitments	$15,985	[3]
[1]	Venture capital and private equity fund investments within non-marketable securities (fair value accounting) include investments made by our managed funds of funds and one of our direct venture funds. These investments represent investments in venture capital and private equity funds that invest primarily in U.S. and global technology and life science & healthcare companies. Included in the fair value and unfunded commitments of fund investments under fair value accounting are $1.1 billion and $555 million, respectively, attributable to noncontrolling interests. It is estimated that we will receive distributions from the fund investments over the next 10 to 13 years, depending on the age of the funds and any potential extensions of terms of the funds.
[2]	Other investments within non-marketable securities (equity method accounting) include investments in debt funds and venture capital and private equity fund investments that invest in or lend money to primarily U.S. and global technology and life science & healthcare companies. It is estimated that we will receive distributions from the fund investments over the next 10 to 13 years, depending on the age of the funds.
[3]	Venture capital and private equity fund investments within non-marketable securities (cost method accounting) include investments in venture capital and private equity fund investments that invest primarily in U.S. and global technology and life science & healthcare companies. It is estimated that we will receive distributions from the fund investments over the next 10 to 13 years, depending on the age of the funds and any potential extensions of the terms of the funds.

Recovered_Sheet6

Fair Value of Financial Instruments - Summary of Estimated Fair Values of Investments and Remaining Unfunded Commitments for Each Major Category of Investments (Textual) (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value	1,484,919
Unfunded Commitments	579,813
Non-marketable securities | Fair value accounting | Venture capital and private equity fund investments
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value	1,195,303	[1]
Unfunded Commitments	557,992	[1]
Non-marketable securities | Equity method accounting | Other investments
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value	51,323	[2]
Unfunded Commitments	5,836	[2]
Non-marketable securities | Cost method accounting | Venture capital and private equity fund investments
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value	238,293	[3]
Unfunded Commitments	15,985	[3]
Non-marketable securities | Noncontrolling Interests | Fair value accounting | Venture capital and private equity fund investments
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value	1,100,000
Unfunded Commitments	555,000
Non-marketable securities | Lower Limit | Fair value accounting | Venture capital and private equity fund investments
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Period distributions from fund investments to be received	10 years
Non-marketable securities | Lower Limit | Equity method accounting | Venture capital and private equity fund investments
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Period distributions from fund investments to be received	10 years
Non-marketable securities | Upper Limit | Fair value accounting | Venture capital and private equity fund investments
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Period distributions from fund investments to be received	13 years
Non-marketable securities | Upper Limit | Equity method accounting | Venture capital and private equity fund investments
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Period distributions from fund investments to be received	13 years
[1]	Venture capital and private equity fund investments within non-marketable securities (fair value accounting) include investments made by our managed funds of funds and one of our direct venture funds. These investments represent investments in venture capital and private equity funds that invest primarily in U.S. and global technology and life science & healthcare companies. Included in the fair value and unfunded commitments of fund investments under fair value accounting are $1.1 billion and $555 million, respectively, attributable to noncontrolling interests. It is estimated that we will receive distributions from the fund investments over the next 10 to 13 years, depending on the age of the funds and any potential extensions of terms of the funds.
[2]	Other investments within non-marketable securities (equity method accounting) include investments in debt funds and venture capital and private equity fund investments that invest in or lend money to primarily U.S. and global technology and life science & healthcare companies. It is estimated that we will receive distributions from the fund investments over the next 10 to 13 years, depending on the age of the funds.
[3]	Venture capital and private equity fund investments within non-marketable securities (cost method accounting) include investments in venture capital and private equity fund investments that invest primarily in U.S. and global technology and life science & healthcare companies. It is estimated that we will receive distributions from the fund investments over the next 10 to 13 years, depending on the age of the funds and any potential extensions of the terms of the funds.