Long-Term Debt (Tables)

9 Months Ended

Sep. 30, 2013

Debt Disclosure [Abstract]

Schedule of Long-term Debt Instruments

Long-term debt consists of the following:

	September 30, 2013			December 31, 2012
	(in thousands)
Senior notes:
3.25% Convertible senior notes due 2016:
Principal amount	$	115,000		$	115,000
Unamortized discount	(10,950		)	(13,671		)
3.25% Convertible senior notes due 2016, net of discount	104,050			101,329
7.75% Senior notes due 2022	500,000			500,000
Total senior notes	604,050			601,329
Credit facilities:
Corporate	—			49,000
PDCM	34,750			26,250
Total credit facilities	34,750			75,250
PDCM second lien term loan	15,000			—
Total debt	653,800			676,579
Less: Current portion of long-term debt	104,050			—
Long-term debt	$	549,750		$	676,579