Financial Instruments - Additional Information (Detail) (USD $)	3 Months Ended
	Mar. 21, 2015	Dec. 27, 2014
Derivative Instruments, Gain (Loss) [Line Items]
Available-for-sale Equity Securities, Accumulated Gross Unrealized Gain, before Tax	$ 126,000,000	$ 111,000,000
Debt Instrument, Fair Value Disclosure	33,000,000,000	31,000,000,000
Call Option For Indirect Equity Percentage	20.00%
Commodity contracts
Derivative Instruments, Gain (Loss) [Line Items]
Derivative maturity term, maximum	3 years
Expected reclassification of net gains (losses) related to hedge from accumulated OCI into net income within the next 12 months	39,000,000
Foreign Exchange Contract
Derivative Instruments, Gain (Loss) [Line Items]
Derivative maturity term, maximum	2 years
Derivative, Notional Amount	2,300,000,000	2,700,000,000
Interest rate derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Notional Amount	7,800,000,000	9,300,000,000
Percentage of total debt, net of related interest rate derivatives, exposed to variable interest rates	31.00%	25.00%
Designated as Hedging Instrument [Member] | Commodity contracts
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Notional Amount	$ 1,100,000,000	$ 1,200,000,000