Acquisition - Preliminary Purchase Price Allocation (Detail) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Business Combinations [Abstract]
Purchase price	$ 46,683
Less: acquired cash	(8,856)
Purchase price, net of acquired cash	37,827
Accounts receivable	3,538
Intangible assets	13,255
Other assets	1,718
Deferred tax liability, net	(2,342)
Accounts payable, accrued expenses and deferred revenue	(4,576)
Goodwill	$ 26,234