Income Taxes Income Tax Contingency (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Income Tax Contingency [Line Items]
Current Fiscal Year End Date	--12-31
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued	$ 1,500,000	$ 3,000,000	$ 2,900,000
Unrecognized Tax Benefits, Increases Resulting from Current Period Tax Positions	1,845,000	1,512,000	1,149,000
Unrecognized Tax Benefits, Increases Resulting from Prior Period Tax Positions	(3,293,000)	4,959,000	2,181,000
Unrecognized Tax Benefits, Decreases Resulting from Settlements with Taxing Authorities	0	0	(555,000)
Unrecognized Tax Benefits, Reductions Resulting from Lapse of Applicable Statute of Limitations	(2,260,000)	(2,430,000)	(1,113,000)
Unrecognized Tax Benefits	$ 10,319,000	$ 14,027,000	$ 9,986,000	$ 8,324,000