Acquisitions - Purchase price allocations (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016	Dec. 29, 2016	Dec. 31, 2015	Aug. 03, 2015
Final purchase price allocation
Goodwill	$ 803	$ 784		$ 601
TIC Gums
Final purchase price allocation
Working capital (excluding cash)			$ 49
Property, plant and equipment			37
Identifiable intangible assets			133
Goodwill			177
Total final purchase price, net of cash			$ 396
Kerr
Final purchase price allocation
Working capital (excluding cash)					$ 37
Property, plant and equipment					8
Other assets					1
Identifiable intangible assets					29
Goodwill					27
Total final purchase price, net of cash					$ 102