Income Taxes (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011
Income Taxes [Abstract]
Effective tax rate (in hundredths)			3.90%	36.50%
Discrete tax expense items			$ 3,600,000
Goodwill and intangible asset impairment	376,574,000	0	376,574,000	0
Impairment of Goodwill and Intangible Assets that Yielded Permanent Tax Differences	255,000,000		255,000,000
Reduction in provision for income taxes			(20,700,000)
Reduction in previously recorded deferred tax liabilities	47,700,000		47,700,000
Annual estimated effective tax rate (in hundredths)	3.90%		3.90%
Gross unrecognized tax benefits	$ 2,900,000		$ 2,900,000		$ 1,700,000