Other Noninterest (Loss) Income and Other Noninterest Expense - Summary of Other Noninterest Income (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	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.