Long-Term Debt (Tables)

6 Months Ended

Jun. 30, 2016

Debt Disclosure [Abstract]

Schedule Of Long-Term Debt

Long-term debt consists of the following:

	June 30, 2016							December 31, 2015
	Principal Amount		Unamortized Discount and Debt Issuance Costs			Net Long-term Debt		Principal Amount		Unamortized Discount and Debt Issuance Costs			Net Long-term Debt
3.60% senior notes due 2022	$	250,000	$	(2,061	)	$	247,939	$	250,000	$	(2,232	)	$	247,768
6 ½% senior notes due 2029	100,000		(952		)	99,048		100,000		(989		)	99,011
6 ¾% senior notes due 2032	250,000		(1,943		)	248,057		250,000		(2,002		)	247,998
6 ½% senior notes due 2035 (the "6 ½%    GO Zone Senior Notes Due 2035")	89,000		(862		)	88,138		89,000		(884		)	88,116
6 ½% senior notes due 2035 (the "6 ½%    IKE Zone Senior Notes Due 2035")	65,000		(618		)	64,382		65,000		(634		)	64,366
Loan related to tax-exempt waste disposal    revenue bonds due 2027	10,889		—			10,889		10,889		—			10,889
Long-term debt, net	$	764,889	$	(6,436	)	$	758,453	$	764,889	$	(6,741	)	$	758,148