Long Term Debt Long Term Debt (Tables)

6 Months Ended

Jun. 30, 2018

Long-term Debt, Unclassified [Abstract]

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

Long-term debt as of June 30, 2018 and December 31, 2017 consists of the following (in thousands):

	June 30, 2018			December 31, 2017
6.0% Senior Notes	$	650,000		$	650,000
3.25% Convertible Notes	402,500			402,500
Less: Unamortized discount	(37,967		)	(42,902		)
Deferred issuance costs	(6,839		)	(7,654		)
Total long-term debt	1,007,694			1,001,944
Less: Current portion	—			—
Total long-term debt, less current portion	$	1,007,694		$	1,001,944