Income Taxes (Details) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Effective income tax provision (in hundredths)	29.30%	17.20%
Statutory U.S. federal income tax (in hundredths)	35.00%	35.00%
Income Tax Examination [Line Items]
Unrecognized Tax Benefits	$ 26,000,000		$ 26,100,000
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued	11,300,000		11.0
Danish tax authority
Income Tax Examination [Line Items]
Cumulative Assessment Amount Including Interest And Penalties	$ 233,300,000
Royalty Rate Assessed on Danish Earnings	20.00%