Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2015	Dec. 31, 2014	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Income Tax Disclosure [Abstract]
Income tax expense	$ 45,340		$ 8,419	$ 58,160	$ 9,971
Loss on extinguishment of Convertible Notes, tax benefit	$ 4,700			$ 7,500
Effective tax rate	36.30%		9.70%	36.30%	8.20%
Tax impacts of extinguishment of Convertible Notes to additional paid in capital	$ 7,500			$ 11,900
Excess tax benefits from stock-based compensation	$ 43,900			$ 57,472	$ 362
Release of valuation allowance for deferred income taxes		$ 33,400