Debt (Tables)

12 Months Ended

Dec. 31, 2017

Debt Disclosure [Abstract]

Summary of Outstanding Note Balances

The outstanding note balance as of December 31, 2017 and 2016 consisted of the following:

(In thousands)	December 31, 2017			December 31, 2016
Liability component:
Principal	$	345,000		$	345,000
Less: debt discount and debt issuance costs , net		(36,195	)		(54,580	)
Net carrying amount		308,805		$	290,420
Equity component	$	61,195		$	61,195

Schedule of Interest Expense Recognized Related to the Notes

The following table sets forth total interest expense recognized related to the Notes for the years ended December 31, 2017 and 2016:

(In thousands)	Year ended December 31,         2017		Year ended December 31,         2016
Contractual interest expense	$	6,038	$	6,038
Amortization of debt issuance costs		871		830
Amortization of debt discount		8,539		8,145
Total interest expense	$	15,448	$	15,013