Long-Term Debt (Tables)

9 Months Ended

Sep. 30, 2019

Debt Disclosure [Abstract]

Schedule of Long-term Debt Instruments

Long-term debt consisted of the following as of:

	September 30, 2019			December 31, 2018
	(in thousands)
Senior Notes:
1.125% Convertible Notes due September 2021:
Principal amount	$	200,000		$	200,000
Unamortized discount	(16,807		)	(22,766		)
Unamortized debt issuance costs	(1,909		)	(2,640		)
Net of unamortized discount and debt issuance costs	181,284			174,594
6.125% Senior Notes due September 2024:
Principal amount	400,000			400,000
Unamortized debt issuance costs	(4,856		)	(5,590		)
Net of unamortized debt issuance costs	395,144			394,410
5.75% Senior Notes due May 2026:
Principal amount	600,000			600,000
Unamortized debt issuance costs	(5,957		)	(6,628		)
Net of unamortized debt issuance costs	594,043			593,372
Total senior notes	1,170,471			1,162,376
Revolving Credit Facility:
Revolving credit facility due May 2023	97,000			32,500
Total long-term debt, net of unamortized discount and debt issuance costs	$	1,267,471		$	1,194,876