Income Taxes (Details) (USD $)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012
Income Tax Examination [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets	$ 181,200,000		$ 181,200,000		$ 25,800,000
Variable Interest Entity, Consolidated, Carrying Amount, Liabilities	181,200,000		181,200,000		25,800,000
Cash Flow (Increase)/Decrease Related to Increase/(Decrease) in Restricted Cash			(15,142,000)	19,306,000	19,200,000
Income Taxes (Textuals) [Abstract]
Gross unrecognized tax benefits (excluding the federal benefit received from state positions)	54,100,000		54,100,000		52,300,000
Decrease in unrecognized tax benefits related to federal, state and foreign tax positions	2,300,000		2,300,000
Effective income tax rate from continuing operations	35.70%	36.60%	35.30%	32.80%
resolution of prior period item [Member]
Income Taxes (Textuals) [Abstract]
Tax impact from one time item	$ 5,000,000
One time item impact as a percentage of earnings before tax	4.10%