Income Taxes (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Income Tax [Line Items]
Taxes recorded in other operating expense	$ 77,986,000	$ 68,144,000	$ 54,866,000
Income Tax (Benefits), Probability Threshold For Recognition, Minimum Percentage	50.00%
Unrecognized Tax Benefits, Impact on Effective Tax Rate if Recognized	147.00%
Unrecognized Tax Benefits, Effective Tax Rate If Fully Recognized	26.36%
Expiration of Statues of Limitation [Member]
Income Tax [Line Items]
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Amount of Unrecorded Benefit	400,000
2011 Tax Filings [Member]
Income Tax [Line Items]
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Amount of Unrecorded Benefit	(500,000)
Net Worth-based Taxes [Member]
Income Tax [Line Items]
Taxes recorded in other operating expense	$ 5,500,000	$ 7,600,000	$ 6,100,000