Income Taxes (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Net unrecognized tax benefit	$ 59,900,000		$ 59,900,000		$ 63,800,000
Income tax interest and penalties accrued	300,000.0		300,000.0
Decrease in unrecognized tax benefits during the period	9,300,000
Deferred tax assets	132,900,000		132,900,000
Effective tax rate	(3.90%)	16.60%	9.00%	8.10%
Unrecognized tax benefits offsetting against short-term tax assets	1,700,000		1,700,000
Unrecognized tax benefits offsetting against long-term deferred tax assets	$ 28,200,000		$ 28,200,000
U.S. federal statutory rate			35.00%