CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (USD $) In Thousands, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2013		Jun. 30, 2012		Jun. 30, 2013		Jun. 30, 2012
Statement of Other Comprehensive Income [Abstract]
Net income	$ 76,522		$ 24,889		$ 93,249		$ 51,225
Reclassification to earnings	746	[1]	(116)	[1]	807	[1]	(1,150)	[1]
Pension liability adjustment	0		0		(3)		0
Total other comprehensive income (loss), net of tax	746		(116)		804		(1,150)
Total comprehensive income	$ 77,268		$ 24,773		$ 94,053		$ 50,075

[1] Reclassification from accumulated other comprehensive income related to de-designated hedges. Refer to Note 10 - Derivative Financial Instruments for further information.