Income Taxes (Details 3) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Income Taxes
Tax reserves related to current year uncertain tax positions	$ 4,100,000
Accrued interest related to current year uncertain tax positions	200,000
Previously recorded tax reserves for uncertain tax positions that have settled and/or closed	6,700,000
Previously recorded accrued interest for uncertain tax positions that have settled and/or closed	3,700,000
Current year tax reverses and accrued interest reversals related to foreign tax positions	7,300,000
Current year tax reverses and accrued interest reversals as reclassification against income taxes payable	2,300,000
Federal deferred tax benefit in the current year associated with its uncertain tax positions	1,900,000
Tax positions that, if reversed, would affect the effective tax rate	21,500,000	32,900,000
Currency translation adjustments for foreign currency tax positions	(39,000)	2,617,000
Interest and penalties recognized, net of deferred taxes	300,000	1,000,000
Reductions in previously accrued interest and penalties	2,300,000
Prepaid income taxes		$ 42,400,000