Restricted Cash (Details) £ in Millions, $ in Millions	Dec. 31, 2016 USD ($)	Dec. 31, 2015 EUR (€)	Dec. 31, 2015 GBP (£)	Dec. 31, 2015 USD ($)	Feb. 19, 2015 GBP (£)
Restricted cash
Total long-term debt | $	$ 7,389			$ 5,028
U.S. Dollar | Rexam
Restricted cash
Invested in escrow account | $				987
British pound | Rexam
Restricted cash
Invested in escrow account			£ 792	$ 1,167
Senior Notes 3.50 Percent Due December 2020
Restricted cash
Total long-term debt | €		€ 400,000,000
Interest rate (as a percent)	3.50%	3.50%	3.50%	3.50%
Debt Instrument, Face Amount | €		€ 400,000,000
Senior Notes 4.375 Percent Due December 2020
Restricted cash
Total long-term debt | $				$ 1,000
Interest rate (as a percent)	4.375%	4.375%	4.375%	4.375%
Debt Instrument, Face Amount | $				$ 1,000
Senior Notes 4.375 Percent Due December 2023
Restricted cash
Total long-term debt | €		€ 700,000,000
Interest rate (as a percent)	4.375%	4.375%	4.375%	4.375%
Debt Instrument, Face Amount | €		€ 700,000,000
Bridge Facility
Restricted cash
Debt Instrument, Face Amount | £			£ 1,900		£ 3,300