Other Liabilities (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Financial Instruments Subject to Mandatory Redemption by Settlement Terms [Line Items]
Asset Acquisition, Gain Recognized, Amount			$ 7.7
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability Value	$ 408.5	$ 312.0	$ 174.8
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Earnings	$ (322.3)	(293.7)
Other Current Liabilities [Member]
Financial Instruments Subject to Mandatory Redemption by Settlement Terms [Line Items]
Synthetic bonds - embedded derivatives		$ 69.7