Other Noninterest Income and Other Noninterest Expense - Summary of Other Noninterest Income (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Other Income and Expenses [Abstract]
Fund management fees	$ 3,559	$ 2,940	$ 6,314	$ 5,709
Service-based fee income	2,252	2,001	4,279	3,805
(Losses) gains on revaluation of foreign currency instruments	(685)	(586)	293	(7,650)
Other (2)	3,636	3,279	9,076	5,323
Total other noninterest income	$ 8,762	$ 7,634	$ 19,962	$ 7,187