Income Taxes Components of Income Tax Expense (Benefit) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Current:
Federal	$ 0	$ (4,894)	$ 3,738
State	3,305	3,002	4,925
Deferred:
Federal	12,114	16,560	10,694
State	123	(102)	(2,617)
Income Tax Expense (Benefit)	$ 15,542	$ 14,566	$ 16,740