Postretirement Benefits - Asset Allocation of Plan Assets of Non-U.S. Plans (Details)	Sep. 30, 2017
Defined Benefit Plan, Information about Plan Assets [Abstract]
Percentage of Plan Assets (as a percent)	100.00%
Cash and cash equivalents
Defined Benefit Plan, Information about Plan Assets [Abstract]
Percentage of Plan Assets (as a percent)	6.00%
Debt securities
Defined Benefit Plan, Information about Plan Assets [Abstract]
Percentage of Plan Assets (as a percent)	62.00%
Equity securities
Defined Benefit Plan, Information about Plan Assets [Abstract]
Percentage of Plan Assets (as a percent)	13.00%
Other
Defined Benefit Plan, Information about Plan Assets [Abstract]
Percentage of Plan Assets (as a percent)	19.00%