Income Taxes (Reconciliation) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Federal statutory tax rate (as a percent)	35.00%
Tax expense (benefit) at statutory federal rate (35%)	$ (159.4)	$ (116.0)	$ 70.7
State income taxes expense (benefit), net of federal tax benefit	(9.8)	(7.7)	5.7
Goodwill impairment	173.8	149.4	0.0
Income Tax Expense (Benefit)	$ 4.6	$ 25.7	$ 76.4