Fair Value of Financial Instruments Additional Information about Level 3 Assets Measured at Fair Value on a Recurring Basis (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Unrealized valuation gains	$ 219,000,000
Non-marketable securities | Fair value accounting | Other venture capital investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Transfers Out of Level 3	(3,561,000)		(7,590,000)
Fair Value, Measurements, Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	859,141,000		799,962,000		547,608,000
Total Realized and Unrealized Gains (Losses) Included in Income	(420,261,000)		(104,712,000)		(176,940,000)
Purchases	149,276,000		135,361,000		170,479,000
Sales	(17,904,000)		(30,793,000)		(53,047,000)
Issuances	9,098,000		11,978,000		13,849,000
Distributions and Other Settlements	(118,235,000)		(153,068,000)		(55,150,000)
Transfers Into Level 3	24,217,000		0		0
Transfers Out of Level 3	(10,903,000)		(9,011,000)		(717,000)
Ending Balance	1,314,951,000		859,141,000		799,962,000
Fair Value, Measurements, Recurring | Equity Warrant Asset, Public Portfolio | Other assets
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	66,129,000	[1]	63,030,000	[1]	43,537,000	[1]
Total Realized and Unrealized Gains (Losses) Included in Income	(22,929,000)	[1]	(13,697,000)	[1]	(31,958,000)	[1]
Purchases	0	[1]	0	[1]	0	[1]
Sales	(16,680,000)	[1]	(21,077,000)	[1]	(25,534,000)	[1]
Issuances	9,098,000	[1]	11,978,000	[1]	13,849,000	[1]
Distributions and Other Settlements	1,540,000	[1]	(78,000)	[1]	(63,000)	[1]
Transfers Into Level 3	24,217,000	[1]	0	[1]	0	[1]
Transfers Out of Level 3	(7,342,000)	[1]	(1,421,000)	[1]	(717,000)	[1]
Ending Balance	99,891,000	[1]	66,129,000	[1]	63,030,000	[1]
Fair Value, Measurements, Recurring | Fair value accounting | Other Securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	0	[2]
Total Realized and Unrealized Gains (Losses) Included in Income	(222,368,000)	[2]
Purchases	0	[2]
Sales	0	[2]
Issuances	0	[2]
Distributions and Other Settlements	96,881,000	[2]
Transfers Into Level 3	0	[2]
Transfers Out of Level 3	0	[2]
Fair Value, Measurements, Recurring | Non-marketable securities | Fair value accounting
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	793,012,000	[3]	736,932,000	[3]	504,071,000	[3]
Total Realized and Unrealized Gains (Losses) Included in Income	(397,332,000)	[3]	(91,015,000)	[3]	(144,982,000)	[3]
Purchases	149,276,000	[3]	135,361,000	[3]	170,479,000	[3]
Sales	(1,224,000)	[3]	(9,716,000)	[3]	(27,513,000)	[3]
Issuances	0	[3]	0	[3]	0	[3]
Distributions and Other Settlements	(119,775,000)	[3]	(152,990,000)	[3]	(55,087,000)	[3]
Transfers Into Level 3	0	[3]	0	[3]	0	[3]
Transfers Out of Level 3	(3,561,000)	[3]	(7,590,000)	[3]	0	[3]
Ending Balance	1,215,060,000	[3]	793,012,000	[3]	736,932,000	[3]
Fair Value, Measurements, Recurring | 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	665,921,000		611,824,000		391,247,000
Total Realized and Unrealized Gains (Losses) Included in Income	(169,219,000)		(44,283,000)		(119,164,000)
Purchases	146,564,000		122,238,000		156,498,000
Sales	0		0		0
Issuances	0		0		0
Distributions and Other Settlements	(118,732,000)		(112,424,000)		(55,085,000)
Transfers Into Level 3	0		0		0
Transfers Out of Level 3	0		0		0
Ending Balance	862,972,000		665,921,000		611,824,000
Fair Value, Measurements, Recurring | Non-marketable securities | Fair value accounting | Other venture capital investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	127,091,000	[2]	124,121,000		111,843,000
Total Realized and Unrealized Gains (Losses) Included in Income	(5,745,000)	[2]	(46,711,000)		(25,794,000)
Purchases	2,712,000	[2]	13,123,000		13,981,000
Sales	(1,224,000)	[2]	(9,716,000)		(27,513,000)
Issuances	0	[2]	0		0
Distributions and Other Settlements	(97,924,000)	[2]	(39,558,000)		16,000
Transfers Into Level 3	0	[2]	0		0
Transfers Out of Level 3	(3,561,000)	[2]	(7,590,000)		0
Ending Balance	32,839,000	[2]	127,091,000	[2]	124,121,000
Fair Value, Measurements, Recurring | Non-marketable securities | Fair value accounting | Other Securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Ending Balance	319,249,000	[2]
Fair Value, Measurements, Recurring | Non-marketable securities | Fair value accounting | Other investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance			987,000		981,000
Total Realized and Unrealized Gains (Losses) Included in Income			(21,000)		(24,000)
Purchases			0		0
Sales			0		0
Issuances			0		0
Distributions and Other Settlements			(1,008,000)		(18,000)
Transfers Into Level 3			0		0
Transfers Out of Level 3			0		0
Ending Balance			$ 0		$ 987,000

[1] Realized and unrealized gains are recorded on the line item “gains on derivative instruments, net”, a component of noninterest income.

[2] Includes total unrealized valuation gains of $219 million attributable to two of our portfolio companies, FireEye and Twitter.

[3] Realized and unrealized gains (losses) are recorded on the line items “gains on investment securities, net”, and “other noninterest income”, components of noninterest income.