Stock Based Awards - Schedule of Stock Based Compensation Allocated to Expense (Detail) (USD $)	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]
Stock based compensation expense	$ 5,117,084	$ 3,088,571	$ 10,281,755	$ 6,073,007
Cost of Revenue [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock based compensation expense	180,702	107,789	383,965	214,970
Research and Development [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock based compensation expense	1,044,848	574,452	2,061,654	1,156,167
Sales and Marketing [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock based compensation expense	2,145,877	900,724	4,226,797	1,850,669
General and Administrative [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock based compensation expense	$ 1,745,657	$ 1,505,606	$ 3,609,339	$ 2,851,201