Long Term Debt Long Term Debt (Tables)

3 Months Ended

Mar. 31, 2018

Long-term Debt, Unclassified [Abstract]

Schedule of Long-term Debt Instruments [Table Text Block]

Long-term debt as of March 31, 2018 and December 31, 2017 consists of the following (in thousands):

	March 31, 2018			December 31, 2017
6.0% Senior Notes	$	650,000		$	650,000
3.25% Convertible Notes	402,500			402,500
Less: Unamortized discount	(40,453		)	(42,902		)
Deferred issuance costs	(7,251		)	(7,654		)
Total long-term debt	1,004,796			1,001,944
Less: Current portion	—			—
Total long-term debt, less current portion	$	1,004,796		$	1,001,944