Income Taxes Schedule of Income Tax Expense (Benefit) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Federal Income Tax Expense (Benefit), Continuing Operations [Abstract]
Current Federal Tax Expense (Benefit)	$ (112.3)	$ (324.0)	$ (92.2)
Deferred Federal Income Tax Expense (Benefit)	34.5	110.3	152.3
State and Local Income Tax Expense (Benefit), Continuing Operations [Abstract]
Current State and Local Tax Expense (Benefit)	(6.6)	(15.5)	(1.4)
Deferred State and Local Income Tax Expense (Benefit)	(9.2)	(3.3)	1.4
Income tax (provision) benefit	$ (93.6)	$ (232.5)	$ 60.1