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Income Taxes - Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014	Mar. 31, 2014
Schedule Of Income Tax [Line Items]
Valuation allowance resulting in income tax benefit	$ 4,326,000		$ 4,326,000		$ 5,618,000	$ 13,725,000
Net deferred tax assets	14,623,000		14,623,000		9,490,000
Unrecognized stock-based compensation	52,547,000		52,547,000		101,108,000
NOLs deemed worthless			3,487,000
Deferred tax asset related to NOLs	0		0
Income tax expense	16,245,000	$ 9,634,000	41,969,000	$ 5,440,000
Gross deferred tax asset	5,133,000	$ 5,472,000	5,133,000	5,472,000
Credit to additional paid-in capital for the amount of NOLs from stock-based compensation			45,706,000	$ 13,649,000
State income taxes	852,000		$ 1,357,000
Income tax rate		38.00%	38.67%
Foreign Subsidiaries [Member]
Schedule Of Income Tax [Line Items]
Deferred tax asset offset by a valuation allowance	$ 1,814,000		$ 1,814,000		$ 816,000
Previously Reported [Member]
Schedule Of Income Tax [Line Items]
Income tax rate		45.00%