Amortization Expense of Acquired Intangibles (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Acquired Finite-Lived Intangible Assets [Line Items]
Total amortization expense	$ 2,777	$ 2,829	$ 5,582	$ 5,699
Cost Of Software License
Acquired Finite-Lived Intangible Assets [Line Items]
Total amortization expense	1,540	1,571	3,108	3,142
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	$ 26	$ 10	$ 93