Pension Benefits (Plan assets) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Jan. 03, 2015	Dec. 28, 2013	Dec. 29, 2012
Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected rates of return	25th percentile
Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected rates of return	75th percentile
Pension [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	$ 5,028	$ 5,014	$ 4,374
Percentage of consolidated plan assets represented by investment in Company common stock	1.30%	1.20%
Expected contributions by company	39
Investment horizon (in years) used to determine expected long-term rate of return on plan assets	20 years
Expected rates of return	57th percentile
Increase in benefit obligation	126
Pension [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	764	901
Pension [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	4,126	3,979
Pension [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	138	134	124
Pension [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	91	111
Pension [Member] | Cash and Cash Equivalents [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	47	28
Pension [Member] | Cash and Cash Equivalents [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	44	83
Pension [Member] | Cash and Cash Equivalents [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	0	0
Pension [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Weighted-average target asset allocation	25.00%
Pension [Member] | Corporate Stock, Common [Member]
Defined Benefit Plan Disclosure [Line Items]
Weighted-average target asset allocation	69.00%
Pension [Member] | Limited partnerships [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	475	468
Pension [Member] | Limited partnerships [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	0	0
Pension [Member] | Limited partnerships [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	475	468
Pension [Member] | Limited partnerships [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	0	0
Pension [Member] | Bonds, Corporate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	519	371
Pension [Member] | Bonds, Corporate [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	0	0
Pension [Member] | Bonds, Corporate [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	519	370
Pension [Member] | Bonds, Corporate [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	0	1	0
Pension [Member] | Bonds, Government [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	172	123
Pension [Member] | Bonds, Government [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	0	0
Pension [Member] | Bonds, Government [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	172	123
Pension [Member] | Bonds, Government [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	0	0
Pension [Member] | Bonds, Other [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	59	52
Pension [Member] | Bonds, Other [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	0	0
Pension [Member] | Bonds, Other [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	59	52
Pension [Member] | Bonds, Other [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	0	0
Pension [Member] | Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	130	125
Pension [Member] | Real Estate [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	0	0
Pension [Member] | Real Estate [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	0	0
Pension [Member] | Real Estate [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	130	125	115
Pension [Member] | Other [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	72	90
Weighted-average target asset allocation	6.00%
Pension [Member] | Other [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	0	0
Pension [Member] | Other [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	64	82
Pension [Member] | Other [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	8	8	9
Postretirement [Member]
Defined Benefit Plan Disclosure [Line Items]
Increase in benefit obligation	33
Domestic [Member] | Pension [Member] | Corporate Stock, Common [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	556	576
Domestic [Member] | Pension [Member] | Corporate Stock, Common [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	556	576
Domestic [Member] | Pension [Member] | Corporate Stock, Common [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	0	0
Domestic [Member] | Pension [Member] | Corporate Stock, Common [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	0	0
Domestic [Member] | Pension [Member] | Collective Trusts, Equity Investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	594	737
Domestic [Member] | Pension [Member] | Collective Trusts, Equity Investments [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	0	0
Domestic [Member] | Pension [Member] | Collective Trusts, Equity Investments [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	594	737
Domestic [Member] | Pension [Member] | Collective Trusts, Equity Investments [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	0	0
Foreign [Member] | Pension [Member] | Corporate Stock, Common [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	161	297
Foreign [Member] | Pension [Member] | Corporate Stock, Common [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	161	297
Foreign [Member] | Pension [Member] | Corporate Stock, Common [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	0	0
Foreign [Member] | Pension [Member] | Corporate Stock, Common [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	0	0
Foreign [Member] | Pension [Member] | Mutual Funds, Equity Investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	393	726
Foreign [Member] | Pension [Member] | Mutual Funds, Equity Investments [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	0	0
Foreign [Member] | Pension [Member] | Mutual Funds, Equity Investments [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	393	726
Foreign [Member] | Pension [Member] | Mutual Funds, Equity Investments [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	0	0
Foreign [Member] | Pension [Member] | Mutual Funds, Debt Investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	0	54
Foreign [Member] | Pension [Member] | Mutual Funds, Debt Investments [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	0	0
Foreign [Member] | Pension [Member] | Mutual Funds, Debt Investments [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	0	54
Foreign [Member] | Pension [Member] | Mutual Funds, Debt Investments [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	0	0
Foreign [Member] | Pension [Member] | Collective Trusts, Equity Investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	1,261	982
Foreign [Member] | Pension [Member] | Collective Trusts, Equity Investments [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	0	0
Foreign [Member] | Pension [Member] | Collective Trusts, Equity Investments [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	1,261	982
Foreign [Member] | Pension [Member] | Collective Trusts, Equity Investments [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	0	0
Foreign [Member] | Pension [Member] | Collective Trusts, Debt Investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	534	288
Foreign [Member] | Pension [Member] | Collective Trusts, Debt Investments [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	0	0
Foreign [Member] | Pension [Member] | Collective Trusts, Debt Investments [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	534	288
Foreign [Member] | Pension [Member] | Collective Trusts, Debt Investments [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	0	0
Eurozone sovereign debt | Pension [Member] | Collective Trusts, Debt Investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	11	14
Eurozone sovereign debt | Pension [Member] | Collective Trusts, Debt Investments [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	0	0
Eurozone sovereign debt | Pension [Member] | Collective Trusts, Debt Investments [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	11	14
Eurozone sovereign debt | Pension [Member] | Collective Trusts, Debt Investments [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	$ 0	$ 0
US High Quality Bonds [Member] | Pension [Member] | Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate assumptions, bond yield percentile	40th percentile
US High Quality Bonds [Member] | Pension [Member] | Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate assumptions, bond yield percentile	90th percentile
Canada And Europe [Member] | Pension [Member] | Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate assumptions, bond yield percentile	10th percentile
Canada And Europe [Member] | Pension [Member] | Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate assumptions, bond yield percentile	90th percentile