Commitments and Contingent Liabilities (Details) $ in Millions	12 Months Ended
	Dec. 31, 2017 USD ($)
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
2018	$ 347.2
2019	290.2
2020	266.2
2021	178.2
2022	124.7
Thereafter	577.1
Total	1,783.6
Less income from subleases	6.3
Net minimum operating lease payments	1,777.3
Guarantor Obligations [Line Items]
Guarantor obligations, maximum exposure, undiscounted	$ 4,603.6
Indirect guarantee of indebtedness
Guarantor Obligations [Line Items]
Guarantor obligations, term	5 years
Financial guarantees
Guarantor Obligations [Line Items]
Guarantor obligations, maximum exposure, undiscounted	$ 933.3	[1]
Performance guarantees
Guarantor Obligations [Line Items]
Guarantor obligations, maximum exposure, undiscounted	$ 3,670.3	[2]

[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.