Pension Benefits (Plan assets) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011 yr	Jan. 01, 2011	Jan. 02, 2010
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	$ 3,931	$ 3,967	$ 3,323
Weighted-average target asset allocation, equity securities	74.00%
Weighted-average target asset allocation, debt securities	23.00%
Weighted-average target asset allocation, other	3.00%
Percentage of consolidated plan assets represented by investment in Company common stock	1.30%
Expected contributions by company	33
Investment horizon (in years) used to determine expected long-term rate of return on plan assets	20
Expected rates of return	62nd percentile
Pension [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	850	999
Pension [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	2,969	2,902
Pension [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	112	66	37
Pension [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	118	207
Pension [Member] | Cash and Cash Equivalents [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	96	169
Pension [Member] | Cash and Cash Equivalents [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	22	38
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] | Bonds, Corporate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	299	351
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	298	350
Pension [Member] | Bonds, Corporate [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	1	1	3
Pension [Member] | Bonds, Government [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	396	180
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	396	180
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	55	29
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	55	29
Pension [Member] | Bonds, Other [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	0	0	4
Pension [Member] | Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	105	58
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	105	58	32
Pension [Member] | Other [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	7	2
Pension [Member] | Other [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	6	0
Pension [Member] | Other [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	(5)	(5)
Pension [Member] | Other [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	6	7	(2)
Domestic [Member] | Pension [Member] | Corporate Stock, Common [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	563	645
Domestic [Member] | Pension [Member] | Corporate Stock, Common [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	563	645
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] | Mutual Funds, Equity Investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	31	44
Domestic [Member] | Pension [Member] | Mutual Funds, Equity Investments [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	0	0
Domestic [Member] | Pension [Member] | Mutual Funds, Equity Investments [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	31	44
Domestic [Member] | Pension [Member] | Mutual Funds, Equity Investments [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	696	600
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	696	600
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
Domestic [Member] | Pension [Member] | Collective Trusts, Debt Investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets		13
Domestic [Member] | Pension [Member] | Collective Trusts, Debt Investments [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets		0
Domestic [Member] | Pension [Member] | Collective Trusts, Debt Investments [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets		13
Domestic [Member] | Pension [Member] | Collective Trusts, Debt Investments [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets		0
Foreign [Member] | Pension [Member] | Corporate Stock, Common [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	185	185
Foreign [Member] | Pension [Member] | Corporate Stock, Common [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	185	185
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	380	419
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	380	419
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] | Collective Trusts, Equity Investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	841	959
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	841	959
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	242	275
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	242	275
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	13
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
Eurozone sovereign debt | Pension [Member] | Collective Trusts, Debt Investments [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan assets	13
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
U.S. High Quality Bonds [Member] | Pension [Member] | Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate assumptions, bond yield percentile	40th percentile
U.S. 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