Income Taxes (Schedule of Provision for Income Taxes for Income from Continuing Operations) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Deferred:
Total, Deferred	$ 53,407	$ 107,032	$ 97,370
Total provision for income taxes for income from continuing operations	157,502	137,653	163,681
Components of provision for income taxes for income from continuing operations [Member]
Current:
Federal	94,080	23,020	54,986
State	10,015	7,601	11,208
Total, Current	104,095	30,621	66,194
Deferred:
Federal	56,487	105,771	92,628
State	(3,080)	1,261	4,859
Total, Deferred	53,407	107,032	97,487
Total provision for income taxes for income from continuing operations	$ 157,502	$ 137,653	$ 163,681