Income Statement Recognition of Share-Based Compensation (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
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation	$ 1,654	$ 2,209	$ 3,903	$ 4,377
Cost of Revenue
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation	194	97	249	243
Selling, General and Administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation	1,345	2,018	3,464	3,940
Research and Development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation	$ 115	$ 94	$ 190	$ 194