Long-term Debt - Schedule of the Liability and Equity Components of the Convertible Senior Notes (Details) - Convertible Notes Payable $ in Thousands	Dec. 31, 2015 USD ($)
Series A Convertible Senior Notes
Debt Instrument [Line Items]
Principal	$ 460,000
Less: Convertible senior notes discounts and issuance costs, net of amortization	(93,469)
Net carrying amount	366,531
Equity component, net of issuance costs	92,567
Series B Convertible Senior Notes
Debt Instrument [Line Items]
Principal	460,000
Less: Convertible senior notes discounts and issuance costs, net of amortization	(120,333)
Net carrying amount	339,667
Equity component, net of issuance costs	$ 117,834