Impairment and Restructuring Charges (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Mar. 31, 2015	Sep. 30, 2015
Restructuring accrual
Restructuring charge for employee severance costs			$ 14
Payments made to terminated employees			(2)
Balance in restructuring reserve at the end of the period	$ 12		$ 12
Expected period of payment of severance costs			12 months
Manufacturing assets in Port Colborne, Ontario, Canada
Restructuring accrual
Restructuring charge for employee severance costs	2		$ 2
Penford
Restructuring accrual
Restructuring charge for employee severance costs		$ 10	10
Consolidation of manufacturing network , Brazil Plant
Restructuring and asset impairment charges
Pre-tax restructuring-related charges	12
Charges for impaired assets	10
Restructuring accrual
Restructuring charge for employee severance costs	$ 2		$ 2