Debt - Total Interest Expense Recognized Related to the Convertible Notes (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Debt Instrument [Line Items]
Amortization of debt discount			$ 0	$ (12,491)
Total interest expense	$ 18,309	$ 14,222	55,002	34,794
Convertible Notes
Debt Instrument [Line Items]
Contractual interest expense	1,250	1,250	3,750	3,750
Amortization of debt issuance costs	273	253	797	733
Amortization of debt discount	1,920	1,777	5,602	5,153
Total interest expense	$ 3,443	$ 3,280	$ 10,149	$ 9,636