Schedule II - Valuation and Qualifying Accounts (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Valuation Allowance of Deferred Tax Assets [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Valuation Allowances and Reserves, Balance	$ 2,238.5	$ 3,334.8	$ 3,372.5	$ 1,152.3
Valuation Allowances and Reserves, Charged to Cost and Expense	(1,104.3)	(40.6)	54.3
Valuation Allowances and Reserves, Charged to Other Accounts	(9.8)	5.1	2,165.9
Valuation Allowances and Reserves, Reserves of Businesses Acquired	17.8	0.0	0.0
Valuation Allowances and Reserves, Deductions	0.0	2.2	0.0
Allowance for Trade Receivables [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Valuation Allowances and Reserves, Balance	0.0	0.0	7.1	$ 0.0
Valuation Allowances and Reserves, Charged to Cost and Expense	0.0	0.0	7.1
Valuation Allowances and Reserves, Charged to Other Accounts	0.0	(7.1)	0.0
Valuation Allowances and Reserves, Reserves of Businesses Acquired	0.0	0.0	0.0
Valuation Allowances and Reserves, Deductions	$ 0.0	$ 0.0	$ 0.0