Consolidated Statements of Comprehensive Income (Loss) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Consolidated Statements of Comprehensive Income (Loss) [Abstract]
Net income (loss)	$ 10,548	$ 47,126	$ (90,190)
Change in fair value of derivative instruments, accounted for as hedges, net of tax benefit (expense) of ($2,388), $1,028 and $13,983, respectively	5,120	(2,857)	(23,792)
Comprehensive income (loss)	$ 15,668	$ 44,269	$ (113,982)