Acquisitions and Divestitures - Acquisitions (Details) - USD ($) $ in Millions	9 Months Ended		12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016	Oct. 31, 2017
Business Acquisitions Information
Purchase price paid for business combinations (net of cash acquired)	$ 12	$ 17
Supplemental information:
Cash paid, net of cash acquired	$ 12	$ 17
Scott Safety
Supplemental information:
Estimated purchase price to acquire business				$ 2,000
Annual sales prior to acquisition			$ 570