Unrealized Gains (Losses) Included in Earnings Attributable to Level 3 Assets Held (Detail) (USD $) In Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2011		Jun. 30, 2011
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Unrealized Gains (Losses) [Line Items]
Unrealized (losses) gains included in earnings attributable to Level 3 assets still held	$ 22,285		$ 57,956
Investment company fair value accounting | Venture capital and private equity fund investments | Non-marketable securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Unrealized Gains (Losses) [Line Items]
Unrealized (losses) gains included in earnings attributable to Level 3 assets still held	19,395		52,731
Investment company fair value accounting | Other venture capital investments | Non-marketable securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Unrealized Gains (Losses) [Line Items]
Unrealized (losses) gains included in earnings attributable to Level 3 assets still held	(1,012)		306
Investment company fair value accounting | Other investments | Non-marketable securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Unrealized Gains (Losses) [Line Items]
Unrealized (losses) gains included in earnings attributable to Level 3 assets still held			20
Investment company fair value accounting | Non-marketable securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Unrealized Gains (Losses) [Line Items]
Unrealized (losses) gains included in earnings attributable to Level 3 assets still held	18,383	[1]	53,057	[1]
Equity warrant assets | Other assets
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Unrealized Gains (Losses) [Line Items]
Unrealized (losses) gains included in earnings attributable to Level 3 assets still held	$ 3,902	[2]	$ 4,899	[2]

[1] Unrealized gains are recorded on the line items gains on investment securities, net and other noninterest income, components of noninterest income.

[2] Unrealized gains are recorded on the line item gains on derivative instruments, net a component of noninterest income.