Consolidated Statements of Comprehensive Income (Unaudited) (USD $) In Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Consolidated Statements of Comprehensive Income [Abstract]
Net income	$ 5,014	$ 6,226	$ 6,433	$ 43,758
Change in fair value of derivative instruments, accounted for as hedges, net of tax benefit (expense) of ($1,423), $109, ($1,753), and ($1,274), respectively	2,402	(186)	4,048	2,117
Comprehensive income	$ 7,416	$ 6,040	$ 10,481	$ 45,875