Debt (Tables)

6 Months Ended

Jun. 30, 2018

Debt Disclosure [Abstract]

Convertible Debt

The Convertible Notes consist of the following (in thousands):

	June 30, 2018			December 31, 2017
Liability component
Principal	$	1,437,483		$	1,437,483
Less: note discount and issuance costs	(31,326		)	(51,159		)
Net carrying amount	$	1,406,157		$	1,386,324
Equity component
Temporary equity	$	28,081		$	—
Additional paid-in capital	134,788			162,869
Total (including temporary equity)	$	162,869		$	162,869

Schedule of Interest Expense Recognized Related to Convertible Notes

The following table includes total interest expense recognized related to the Convertible Notes and the 2027 Notes (in thousands):

	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2018		2017		2018		2017
Contractual interest expense	$	10,327	$	1,797	$	20,562	$	3,594
Amortization of debt issuance costs	1,374		1,039		2,379		2,071
Amortization of debt discount	8,811		8,472		17,476		16,882
	$	20,512	$	11,308	$	40,417	$	22,547