Loans - Summary of Changes in Allowance for Loan Losses (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
Allowance For Loan And Lease Losses [Roll Forward]
Balance, beginning of period				$ 26,977				$ 18,122	$ 26,977	$ 18,122	$ 12,508
Provision charged to operations	2,400	2,400	2,400	2,600	4,800	1,800	1,800	2,635	9,800	11,035	8,010
Charge-offs									(4,769)	(2,561)	(2,462)
Recoveries									135	381	66
Balance, end of period	$ 32,143				$ 26,977				$ 32,143	$ 26,977	$ 18,122