Operating Leases (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Operating Leases
Rent expense attributable to warehouse, office buildings and equipment operating leases	$ 80	$ 72	$ 63
Minimum future rentals under operating leases
2017	65
2018	47
2019	32
2020	23
2021	14
2022 and thereafter	$ 24