Income Taxes (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Income Taxes [Abstract]
Effective income tax provision (in hundredths)	17.20%	31.10%
Statutory U.S. federal income tax (in hundredths)	35.00%	35.00%
Deferred tax liabilities			$ 48.1
Tax recognized on the repatriation transaction	37.1
Tax benefit recognized on the repatriation	11.0
Income tax assessment from Danish Tax Authority	$ 185.9