Summary of Change in Fair Value of Level Three Assets (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Unrealized gain (loss) recognized in other expenses	$ 300	$ (2)	$ 459	$ (21)
Indemnification Assets [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	2,114	4,540	3,586	6,099
Payments received	(196)	(369)	(1,495)	(1,947)
Unrealized gain (loss) recognized in other expenses	(286)	2	(459)	21
Ending balance	$ 1,632	$ 4,173	$ 1,632	$ 4,173