Amortization Expense of Acquired Intangibles (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Acquired Finite-Lived Intangible Assets [Line Items]
Total amortization expense	$ 2,773	$ 2,777	$ 5,550	$ 5,582
Cost of software license
Acquired Finite-Lived Intangible Assets [Line Items]
Total amortization expense	1,541	1,540	3,082	3,108
Selling and marketing
Acquired Finite-Lived Intangible Assets [Line Items]
Total amortization expense	1,232	1,232	2,464	2,464
General and administrative
Acquired Finite-Lived Intangible Assets [Line Items]
Total amortization expense		$ 5	$ 4	$ 10