Income Taxes (Details) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Net unrecognized tax benefit	$ 68,600,000		$ 63,800,000
Income tax interest and penalties accrued	0
Deferred tax assets	107,000,000
Effective tax rate	18.60%	(3.30%)
Tax benefit expected to be recognized in the first quarter of 2013 under the provisions of the American Taxpayer Relief Act of 2012		9,400,000
Unrecognized tax benefits offsetting against short-term deferred tax assets	1,700,000
Unrecognized tax benefits offsetting against long-term deferred tax assets	$ 28,200,000
U.S. federal statutory rate	35.00%