Income Taxes Uncertain Tax Positions (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2008
Income Taxes [Abstract]
Unrecognized tax benefits at beginning of year	$ 17,091	$ 18,034	$ 27,700	$ 66,902
Additions based on tax positions related to the current year	1,219	1,532	631
Additions for tax positions of prior years	5,212	3,100	1,062
Reductions for tax positions of prior years	(492)	(1,634)	(2,405)
Settlement reductions	(5,330)	0	(2,042)
Reductions for tax positions settled through the expirations of the statute of limitations	$ (1,552)	$ (12,664)	$ (36,448)