Pension, Retiree Medical and Savings Plans (Categorized Plan Assets Measured at Fair Value) (Details) $ in Millions		12 Months Ended
		Dec. 30, 2017 USD ($)		Dec. 31, 2018 USD ($)	Dec. 31, 2016 USD ($)	Dec. 26, 2015 USD ($)
US Plan Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[1]	$ 12,903			$ 11,778
Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		3,460			2,894	$ 2,823
Domestic Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		12,582			11,458	11,397
Postretirement Health Coverage [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		321			320	$ 354
U.S. Equity securities, including preferred stock | Level 1 | Domestic Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[1],[2]	6,896
U.S. Equity securities, including preferred stock | Level 2 | Domestic Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[1],[2]	8
Fixed Income Commingled funds [Member] | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[3]	383			316
Fixed Income Commingled funds [Member] | Level 1 | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[3]	383
Fixed Income Commingled funds [Member] | Level 2 | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[3]	0
Fixed Income Commingled funds [Member] | Level 3 | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[3]	0
Mortgage-backed Securities, Issued by Private Enterprises [Member] | Domestic Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[4]	217			187
Mortgage-backed Securities, Issued by Private Enterprises [Member] | Level 1 | Domestic Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[4]	0
Mortgage-backed Securities, Issued by Private Enterprises [Member] | Level 2 | Domestic Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[4]	217
Mortgage-backed Securities, Issued by Private Enterprises [Member] | Level 3 | Domestic Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[4]	0
US Government Agencies Debt Securities [Member] | Domestic Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[4]	1,365			1,173
US Government Agencies Debt Securities [Member] | Level 1 | Domestic Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[4]	0
US Government Agencies Debt Securities [Member] | Level 2 | Domestic Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[4]	1,365
US Government Agencies Debt Securities [Member] | Level 3 | Domestic Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[4]	0
Corporate Bonds [Member] | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[4]	493			453
Corporate Bonds [Member] | Domestic Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[4]	3,429			3,012
Corporate Bonds [Member] | Level 1 | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[4]	0
Corporate Bonds [Member] | Level 1 | Domestic Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[4]	0
Corporate Bonds [Member] | Level 2 | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[4]	493
Corporate Bonds [Member] | Level 2 | Domestic Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[4]	3,429
Corporate Bonds [Member] | Level 3 | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[4]	0
Corporate Bonds [Member] | Level 3 | Domestic Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[4]	0
Government Securities | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[3],[4]	492			$ 432
Government Securities | Level 1 | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[3],[4]	0
Government Securities | Level 2 | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[3],[4]	492
Government Securities | Level 3 | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[3],[4]	$ 0
Corporate Bonds
Defined Benefit Plan Disclosure [Line Items]
Representation of one fund in total U.S. plan assets		23.00%			22.00%
Contracts With Insurance Companies | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[5]	$ 36			$ 35
Contracts With Insurance Companies | Domestic Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[1],[5]	8			7
Contracts With Insurance Companies | Level 1 | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[5]	0
Contracts With Insurance Companies | Level 1 | Domestic Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[1],[5]	0
Contracts With Insurance Companies | Level 2 | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[5]	0
Contracts With Insurance Companies | Level 2 | Domestic Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[1],[5]	0
Contracts With Insurance Companies | Level 3 | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[5]	36
Contracts With Insurance Companies | Level 3 | Domestic Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[1],[5]	8
Cash And Cash Equivalents | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		19			12
Cash And Cash Equivalents | Domestic Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[1]	236			196
Cash And Cash Equivalents | Level 1 | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		19
Cash And Cash Equivalents | Level 1 | Domestic Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[1]	236
Cash And Cash Equivalents | Level 2 | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0
Cash And Cash Equivalents | Level 2 | Domestic Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[1]	0
Cash And Cash Equivalents | Level 3 | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0
Cash And Cash Equivalents | Level 3 | Domestic Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[1]	0
Sub-Total U.S. Plan Assets | Domestic Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[1]	12,159			11,064
Sub-Total U.S. Plan Assets | Level 1 | Domestic Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[1]	7,132
Sub-Total U.S. Plan Assets | Level 2 | Domestic Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[1]	5,019
Sub-Total U.S. Plan Assets | Level 3 | Domestic Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[1]	8
Real Estate Funds [Member] | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[6]	102			84
Real Estate Funds [Member] | Domestic Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[6]	675	[1]		651
Sub-Total International Plan Assets | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		3,351			2,804
Sub-Total International Plan Assets | Level 1 | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		2,297
Sub-Total International Plan Assets | Level 2 | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		1,018
Sub-Total International Plan Assets | Level 3 | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		36
Dividends And Interest Receivable | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		7			6
Dividends And Interest Receivable | Domestic Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[1]	69			63
Equity Securities [Member] | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		1,928	[2]		1,556
Equity Securities [Member] | Domestic Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		6,904	[2]		$ 6,489
Equity Securities [Member] | Level 1 | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[2]	1,895
Equity Securities [Member] | Level 2 | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[2]	33
Equity Securities [Member] | Level 3 | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[2]	0
Equity Securities [Member] | Level 3 | Domestic Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		$ 0
Large-Cap Fund(s) In U.S. Commingled Funds
Defined Benefit Plan Disclosure [Line Items]
Representation of one fund in total U.S. plan assets		19.00%			19.00%
Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Redemption period - Min		45
Redemption period		90
Subsequent Event [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year				$ 1,400
Subsequent Event [Member] | Funded Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year				800
Subsequent Event [Member] | Unfunded Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year				$ 700

[1] 2017 and 2016 amounts include $321 million and $320 million, respectively, of retiree medical plan assets that are restricted for purposes of providing health benefits for U.S. retirees and their beneficiaries.

[2] The equity securities portfolio was invested in U.S. and international common stock and commingled funds, and the preferred stock portfolio in the U.S. was invested in domestic and international corporate preferred stock investments. The common stock is based on quoted prices in active markets. The U.S. commingled funds are based on fair values of the investments owned by these funds that are benchmarked against various U.S. large, mid-cap and small company indices, and includes one large-cap fund that represents 19% of total U.S. plan assets for 2017 and 2016. The international commingled funds are based on the fair values of the investments owned by these funds that track various non-U.S. equity indices. The preferred stock investments are based on quoted bid prices for comparable securities in the marketplace and broker/dealer quotes in active markets.

[3] Based on the fair value of the investments owned by these funds that track various government and corporate bond indices.

[4] These investments are based on quoted bid prices for comparable securities in the marketplace and broker/dealer quotes in active markets. Corporate bonds of U.S.-based companies represent 23% and 22% of total U.S. plan assets for 2017 and 2016, respectively.

[5] Based on the fair value of the contracts as determined by the insurance companies using inputs that are not observable. The changes in Level 3 amounts were not significant in the years ended December 30, 2017 and December 31, 2016.

[6] The real estate commingled funds include investments in limited partnerships. These funds are based on the net asset value of the appraised value of investments owned by these funds as determined by independent third parties using inputs that are not observable. The majority of the funds are redeemable quarterly subject to availability of cash and have notice periods ranging from 45 to 90 days.