Retirement Plans and Other Retiree Benefits (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009
Allocation of plan assets and level of valuation input for each major asset category [Abstract]
Percentage of fixed income portfolio invested in U.S. treasury or agency securities (in hundredths)	75.00%		75.00%
United States Pension Benefits [Member]
Defined Benefit Plan, Assets, Target Allocations [Abstract]
Equity securities (in hundredths)	52.00%
Debt securities (in hundredths)	40.00%
Real estate and alternative investments (in hundredths)	8.00%
Total (in hundredths)	100.00%
Allocation of plan assets and level of valuation input for each major asset category [Abstract]
Total investments at fair value	$ 1,426		$ 1,377		$ 1,300
United States Pension Benefits [Member] | Cash & cash equivalents [Member] | Level 1 [Member]
Allocation of plan assets and level of valuation input for each major asset category [Abstract]
Total investments at fair value	67		84
United States Pension Benefits [Member] | U.S. common stocks [Member] | Level 1 [Member]
Allocation of plan assets and level of valuation input for each major asset category [Abstract]
Total investments at fair value	209		223
United States Pension Benefits [Member] | International common stocks [Member] | Level 1 [Member]
Allocation of plan assets and level of valuation input for each major asset category [Abstract]
Total investments at fair value	47		55
United States Pension Benefits [Member] | Fixed income securities [Member] | Level 2 [Member]
Allocation of plan assets and level of valuation input for each major asset category [Abstract]
Total investments at fair value	145	[1]	142	[1]
United States Pension Benefits [Member] | Equity index funds [Member] | Level 2 [Member]
Allocation of plan assets and level of valuation input for each major asset category [Abstract]
Total investments at fair value	405	[2]	314	[2]
United States Pension Benefits [Member] | Emerging market equity index funds [Member] | Level 2 [Member]
Allocation of plan assets and level of valuation input for each major asset category [Abstract]
Total investments at fair value	54	[2]	61	[2]
United States Pension Benefits [Member] | Other common stock funds [Member] | Level 2 [Member]
Allocation of plan assets and level of valuation input for each major asset category [Abstract]
Total investments at fair value	34	[2]	95	[2]
United States Pension Benefits [Member] | Fixed income funds: U.S. or foreign government and agency securities [Member] | Level 2 [Member]
Allocation of plan assets and level of valuation input for each major asset category [Abstract]
Total investments at fair value	268	[2]	222	[2]
United States Pension Benefits [Member] | Fixed income funds: investment grade corporate bonds [Member] | Level 2 [Member]
Allocation of plan assets and level of valuation input for each major asset category [Abstract]
Total investments at fair value	58	[2]	59	[2]
United States Pension Benefits [Member] | Fixed income funds: high yield corporate bonds and other [Member] | Level 2 [Member]
Allocation of plan assets and level of valuation input for each major asset category [Abstract]
Total investments at fair value	75	[2]	67	[2]
United States Pension Benefits [Member] | Guaranteed investment contracts [Member] | Level 2 [Member]
Allocation of plan assets and level of valuation input for each major asset category [Abstract]
Total investments at fair value	2	[3]	0	[3]
United States Pension Benefits [Member] | Real estate [Member] | Level 3 [Member]
Allocation of plan assets and level of valuation input for each major asset category [Abstract]
Total investments at fair value	62	[4]	55	[4]
International Pension Benefits [Member]
Defined Benefit Plan, Assets, Target Allocations [Abstract]
Equity securities (in hundredths)	43.00%
Debt securities (in hundredths)	46.00%
Real estate and alternative investments (in hundredths)	11.00%
Total (in hundredths)	100.00%
Allocation of plan assets and level of valuation input for each major asset category [Abstract]
Total investments at fair value	437		434		401
International Pension Benefits [Member] | Cash & cash equivalents [Member] | Level 1 [Member]
Allocation of plan assets and level of valuation input for each major asset category [Abstract]
Total investments at fair value	12		14
International Pension Benefits [Member] | U.S. common stocks [Member] | Level 1 [Member]
Allocation of plan assets and level of valuation input for each major asset category [Abstract]
Total investments at fair value	0		0
International Pension Benefits [Member] | International common stocks [Member] | Level 1 [Member]
Allocation of plan assets and level of valuation input for each major asset category [Abstract]
Total investments at fair value	0		0
International Pension Benefits [Member] | Fixed income securities [Member] | Level 2 [Member]
Allocation of plan assets and level of valuation input for each major asset category [Abstract]
Total investments at fair value	0	[1]	0	[1]
International Pension Benefits [Member] | Equity index funds [Member] | Level 2 [Member]
Allocation of plan assets and level of valuation input for each major asset category [Abstract]
Total investments at fair value	158	[2]	166	[2]
International Pension Benefits [Member] | Emerging market equity index funds [Member] | Level 2 [Member]
Allocation of plan assets and level of valuation input for each major asset category [Abstract]
Total investments at fair value	17	[2]	18	[2]
International Pension Benefits [Member] | Other common stock funds [Member] | Level 2 [Member]
Allocation of plan assets and level of valuation input for each major asset category [Abstract]
Total investments at fair value	28	[2]	13	[2]
International Pension Benefits [Member] | Fixed income funds: U.S. or foreign government and agency securities [Member] | Level 2 [Member]
Allocation of plan assets and level of valuation input for each major asset category [Abstract]
Total investments at fair value	82	[2]	88	[2]
International Pension Benefits [Member] | Fixed income funds: investment grade corporate bonds [Member] | Level 2 [Member]
Allocation of plan assets and level of valuation input for each major asset category [Abstract]
Total investments at fair value	75	[2]	71	[2]
International Pension Benefits [Member] | Fixed income funds: high yield corporate bonds and other [Member] | Level 2 [Member]
Allocation of plan assets and level of valuation input for each major asset category [Abstract]
Total investments at fair value	1	[2]	1	[2]
International Pension Benefits [Member] | Guaranteed investment contracts [Member] | Level 2 [Member]
Allocation of plan assets and level of valuation input for each major asset category [Abstract]
Total investments at fair value	46	[3]	47	[3]
International Pension Benefits [Member] | Real estate [Member] | Level 3 [Member]
Allocation of plan assets and level of valuation input for each major asset category [Abstract]
Total investments at fair value	18	[4]	16	[4]	11
Other Retiree Benefits [Member]
Allocation of plan assets and level of valuation input for each major asset category [Abstract]
Total investments at fair value	32		32		28
Other Retiree Benefits [Member] | Cash & cash equivalents [Member] | Level 1 [Member]
Allocation of plan assets and level of valuation input for each major asset category [Abstract]
Total investments at fair value	2		2
Other Retiree Benefits [Member] | U.S. common stocks [Member] | Level 1 [Member]
Allocation of plan assets and level of valuation input for each major asset category [Abstract]
Total investments at fair value	5		6
Other Retiree Benefits [Member] | International common stocks [Member] | Level 1 [Member]
Allocation of plan assets and level of valuation input for each major asset category [Abstract]
Total investments at fair value	1		1
Other Retiree Benefits [Member] | Fixed income securities [Member] | Level 2 [Member]
Allocation of plan assets and level of valuation input for each major asset category [Abstract]
Total investments at fair value	0	[1]	0	[1]
Other Retiree Benefits [Member] | Equity index funds [Member] | Level 2 [Member]
Allocation of plan assets and level of valuation input for each major asset category [Abstract]
Total investments at fair value	10	[2]	8	[2]
Other Retiree Benefits [Member] | Emerging market equity index funds [Member] | Level 2 [Member]
Allocation of plan assets and level of valuation input for each major asset category [Abstract]
Total investments at fair value	1	[2]	2	[2]
Other Retiree Benefits [Member] | Other common stock funds [Member] | Level 2 [Member]
Allocation of plan assets and level of valuation input for each major asset category [Abstract]
Total investments at fair value	1	[2]	3	[2]
Other Retiree Benefits [Member] | Fixed income funds: U.S. or foreign government and agency securities [Member] | Level 2 [Member]
Allocation of plan assets and level of valuation input for each major asset category [Abstract]
Total investments at fair value	7	[2]	6	[2]
Other Retiree Benefits [Member] | Fixed income funds: investment grade corporate bonds [Member] | Level 2 [Member]
Allocation of plan assets and level of valuation input for each major asset category [Abstract]
Total investments at fair value	1	[2]	2	[2]
Other Retiree Benefits [Member] | Fixed income funds: high yield corporate bonds and other [Member] | Level 2 [Member]
Allocation of plan assets and level of valuation input for each major asset category [Abstract]
Total investments at fair value	2	[2]	2	[2]
Other Retiree Benefits [Member] | Guaranteed investment contracts [Member] | Level 2 [Member]
Allocation of plan assets and level of valuation input for each major asset category [Abstract]
Total investments at fair value	0	[3]	0	[3]
Other Retiree Benefits [Member] | Real estate [Member] | Level 3 [Member]
Allocation of plan assets and level of valuation input for each major asset category [Abstract]
Total investments at fair value	$ 2	[4]	$ 0	[4]

[1] The fixed income securities are traded over the counter and a small portion of the securities lack daily pricing or liquidity and as such are classified as Level 2. As of December 31, 2011 and 2010, approximately 75% of the fixed income portfolio was invested in U.S. treasury or agency securities, with the remainder invested in corporate bonds.

[2] Interests in common/collective trust funds are valued using the net asset value (NAV) per unit in each fund. The NAV is based on the value of the underlying investments owned by each trust, minus its liabilities, divided by the number of shares outstanding.

[3] The guaranteed investment contracts (GICs) represent contracts with insurance companies measured at the cash surrender value of each contract. The Level 2 valuation reflects that the cash surrender value is based principally on a referenced pool of investment funds with active redemption.

[4] Real estate is valued using the NAV per unit of funds that are invested in real property, and the real property is valued using independent market appraisals. Since the appraisals include unobservable inputs, the investments in each fund are classified as Level 3.