Other Noninterest Income and Other Noninterest Expense - Summary of Other Noninterest Expense (Detail) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015		Jun. 30, 2014
Other Income and Expenses [Abstract]
Lending and other client related processing costs		$ 3,704	$ 2,586	$ 7,253		$ 4,945
Telephone		2,544	1,538	4,503		3,286
Data processing services		1,358	2,041	3,191		4,268
Postage and supplies		727	716	1,492		1,485
Dues and publications		697	636	1,282		1,133
Other (1)		5,279	3,108	10,110		4,670
Total other noninterest expense	[1]	$ 14,309	$ 10,625	$ 27,831	[2]	$ 19,787

[1] Prior period amounts have been revised to reflect the retrospective application of new accounting guidance adopted in the first quarter of 2015 related to our investments in qualified affordable housing projects (ASU 2014-01). See Note 1— "Basis of Presentation" of the "Notes to Interim Consolidated Financial Statements" under Part I, Item 1 in this report.

[2] {F|ahBzfndlYmZpbGluZ3MtaHJkcmoLEgZYTUxEb2MiXlhCUkxEb2NHZW5JbmZvOjA2NWJiNjIxZjM0ZjRmOWVhYzRkYjZjMWUyZjAzZTk2fFRleHRTZWxlY3Rpb246ODVBMjJCNzk0NDdCOEEwRjQ3QTIwMTA2RUZDRUFERDEM}