Valuation and Qualifying Accounts (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Valuation Allowance of Deferred Tax Assets [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Valuation Allowances and Reserves, Balance, Beginning Balance	$ 112.0	$ 102.2	$ 10.1
Valuation Allowances and Reserves, Charged to Cost and Expense	23.7	15.9	23.5
Valuation Allowances and Reserves, Charged to Other Accounts	(8.6)	(6.1)	68.6
Valuation Allowances and Reserves, Deductions	0.0	0.0	0.0
Valuation Allowances and Reserves, Balance, Ending Balance	127.1	112.0	102.2
Allowance for Loan and Lease Losses, Real Estate [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Valuation Allowances and Reserves, Balance, Beginning Balance	6.5	10.1	11.6
Valuation Allowances and Reserves, Charged to Cost and Expense	0.3	(0.9)	1.9
Valuation Allowances and Reserves, Charged to Other Accounts	0.0	0.0	0.0
Valuation Allowances and Reserves, Deductions	0.0	2.7	3.4
Valuation Allowances and Reserves, Balance, Ending Balance	$ 6.8	$ 6.5	$ 10.1