Components of Other Operating Expense (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Component of Operating Other Cost and Expense [Abstract]
Service fees									$ 3,157		$ 3,736		$ 2,941
Professional fees									2,564		1,912		1,554
Telephone and data communications									1,707		1,548		1,616
Advertising and public relations									1,686		1,421		1,683
ATM processing expenses									1,605		1,483		1,515
Premises and equipment write-downs									1,520				131
Office supplies									1,472		1,688		1,222
Other									9,538	[1]	9,402	[1]	9,643	[1]
Total other operating expense	$ 20,755	$ 20,153	$ 18,533	$ 19,544	$ 21,733	$ 20,325	$ 20,132	$ 16,193	$ 23,249		$ 21,190		$ 20,305

[1] Other components of other operating income do not exceed 1% of total income.