Other Noninterest Income and Other Noninterest Expense - Summary of Other Noninterest Income (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013		Mar. 31, 2012
Other Income and Expenses [Abstract]
Unused commitment fees	$ 3,476		$ 3,055
Fund management fees	2,769		2,828
Service-based fee income	1,804		2,374
(Losses) gains on revaluation of foreign currency instruments	(7,064)	[1]	1,885	[1]
Currency revaluation (losses) gains	(55)	[2]	615	[2]
Other	2,597		2,321
Total other noninterest income	$ 3,527		$ 13,078

[1] Represents the revaluation of foreign currency denominated financial instruments issued and held by us, primarily loans, deposits and cash.

[2] Includes the revaluation of foreign currency denominated assets of certain fund investments. Included in these amounts are gains of $0.2 million and $0.6 million for the three months ended March 31, 2013 and 2012, respectively, attributable to noncontrolling interests calculated based on the ownership percentages of the noncontrolling interests.