Commitments and Contingencies - Summary of Rental Expense Charged to Operations (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Operating Leases Rent Expense [Abstract]
Rental expense	$ 2,304	$ 2,250	$ 2,169
Sublease rental income	(278)	(396)	(371)
Net rental expense	$ 2,026	$ 1,854	$ 1,798