Commitments and Contingent Liabilities (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2019	Dec. 31, 2018
Guarantor Obligations
Guarantor obligations, maximum exposure, undiscounted		$ 4,904.9	$ 4,798.0
Estimated Litigation Liability			280.0
Indirect guarantee of indebtedness
Guarantor Obligations
Guarantor obligations, term of obligation		P5Y
Financial guarantees
Guarantor Obligations
Guarantor obligations, maximum exposure, undiscounted	[1]	$ 738.4	750.4
Performance guarantees
Guarantor Obligations
Guarantor obligations, maximum exposure, undiscounted	[2]	$ 4,166.5	$ 4,047.6

[1] Financial guarantees represent contracts that contingently require a guarantor to make payments to a guaranteed party based on changes in an underlying agreement that is related to an asset, a liability or an equity security of the guaranteed party. These tend to be drawn down only if there is a failure to fulfill our financial obligations.

[2] Performance guarantees represent contracts that contingently require a guarantor to make payments to a guaranteed party based on another entity's failure to perform under a nonfinancial obligating agreement. Events that trigger payment are performance-related, such as failure to ship a product or provide a service.