Income Taxes (Provision (Benefit) for Income Taxes) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Current:
Federal Current	$ 15,500		$ 3,378		$ 10,421
State Current	3,189		820		1,518
Current	18,689		4,198		11,939
Deferred:
Federal Deferred	(388,209)		345,922		319,279
State Deferred	(71,582)		60,941		59,982
Foreign Deferred	(2,037)		2,160		459
Deferred	(461,828)		409,023		379,720
Provision (benefit) for income taxes	$ (443,139)	[1]	$ 413,221	[1]	$ 391,659	[1]

[1] Interest income, interest expense and the provision (benefit) for income taxes by segment are an allocation of corporate amounts as cash equivalents, debt and income tax expense allocated as they are incurred at the corporate level.