Income Taxes (Provision) (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Current tax expense:
Federal	$ 79,000,000	$ (3,400,000)	$ 77,800,000
State	12,500,000	(1,200,000)	14,500,000
Total current tax expense	91,500,000	(4,600,000)	92,300,000
Deferred tax expense (benefit):
Federal	15,000,000	11,100,000	5,100,000
State	(6,400,000)	(2,200,000)	2,700,000
Total deferred tax expense (benefit)	8,645,000	8,924,000	7,771,000
Interest expense, gross of related tax effects	(300,000)	1,700,000	600,000
Total income tax provision	$ 99,827,000	$ 5,969,000	$ 100,708,000