Debt (Summary of Outstanding Debt) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2015 USD ($)	Dec. 31, 2015 EUR (€)	May. 31, 2015 USD ($)	May. 31, 2015 EUR (€)	Dec. 31, 2014 USD ($)	Dec. 31, 2014 EUR (€)	Jul. 31, 2014 USD ($)	Jul. 31, 2014 EUR (€)
Debt Instrument [Line Items]
Short-term debt	$ 54				$ 75
Principal outstanding
Total long-term debt	5,528				5,186
Less: current maturities	(211)				(177)
Total long-term debt, less current maturities	5,317				5,009
Carrying amount
Total long-term debt	5,464				5,119
Less: current maturities	(209)				(175)
Total long-term debt, less current maturities	5,255				4,944
Line of Credit [Member]
Principal outstanding
Total long-term debt	0				0
Carrying amount
Total long-term debt	0				0
Senior Secured Borrowings [Member] | U.S. Dollar at LIBOR plus 1.75% due 2018 [Member]
Principal outstanding
Total long-term debt	831				800
Carrying amount
Total long-term debt	$ 821				787
Basis spread on variable rate (as a percent)	1.75%
Senior Secured Borrowings [Member] | Euro at EURIBOR plus 1.75% due 2018 [Member]
Principal outstanding
Total long-term debt	$ 723				847
Carrying amount
Total long-term debt	$ 714				834
Basis spread on variable rate (as a percent)	1.75%
Debt instrument, face amount | €		€ 665,000,000				€ 700,000,000
Senior Secured Borrowings [Member] | Farm Credit Facility at LIBOR Plus 2.00% due 2019 [Member]
Principal outstanding
Total long-term debt	$ 355				358
Carrying amount
Total long-term debt	$ 350				351
Basis spread on variable rate (as a percent)	2.00%
Senior Notes and Debentures [Member] | U.S. Dollar 6.25% due 2021 [Member]
Principal outstanding
Total long-term debt	$ 700				700
Carrying amount
Total long-term debt	$ 694				693
Debt instrument stated percentage	6.25%	6.25%
Senior Notes and Debentures [Member] | Euro 4.0% due 2022 [Member]
Principal outstanding
Total long-term debt	$ 706				786		$ 706	€ 650,000,000
Carrying amount
Total long-term debt	$ 697				775
Debt instrument stated percentage	4.00%	4.00%					4.00%	4.00%
Debt instrument, face amount | €		€ 650,000,000
Senior Notes and Debentures [Member] | U.S. Dollar 4.50% due 2023 [Member]
Principal outstanding
Total long-term debt	$ 1,000				1,000
Carrying amount
Total long-term debt	$ 989				988
Debt instrument stated percentage	4.50%	4.50%
Senior Notes and Debentures [Member] | Euro 3.375% due 2025 [Member]
Principal outstanding
Total long-term debt	$ 652		$ 652	€ 600,000,000	0
Carrying amount
Total long-term debt	$ 642				0
Debt instrument stated percentage	3.375%	3.375%	3.375%	3.375%
Debt instrument, face amount | €		€ 600,000,000
Senior Notes and Debentures [Member] | U.S. Dollar 7.375% due 2026 [Member]
Principal outstanding
Total long-term debt	$ 350				350
Carrying amount
Total long-term debt	$ 346				346
Debt instrument stated percentage	7.375%	7.375%
Senior Notes and Debentures [Member] | U.S. Dollar 7.50% due 2096 [Member]
Principal outstanding
Total long-term debt	$ 45				64
Carrying amount
Total long-term debt	$ 45				64
Debt instrument stated percentage	7.50%	7.50%
Other Indebtedness, Fixed Rate [Member]
Principal outstanding
Total long-term debt	$ 146				211
Carrying amount
Total long-term debt	$ 146				211
Fixed rate, minimum (as a percent)	1.00%
Fixed rate, maximum (as a percent)	8.50%
Other Indebtedness, Variable Rate [Member]
Principal outstanding
Total long-term debt	$ 20				70
Carrying amount
Total long-term debt	$ 20				$ 70
Variable rate, minimum (as a percent)	3.40%
Variable rate, maximum (as a percent)	5.10%