Retirement Plans and Profit Sharing Arrangements (Details 3) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Private real estate investment trust
Defined Benefit Plan Disclosure
Fair Value of Plan Assets		$ 8
Pension Plans
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	362	327	256
Pension Plans | Private real estate investment trust
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	11	8	5
Pension Plans | Hedge funds
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	12	9
Pension Plans | Level 1
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	169	163
Pension Plans | Level 1 | U.S. large cap stocks
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	75	72
Pension Plans | Level 1 | U.S. small cap stocks
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	38	33
Pension Plans | Level 1 | Non-U.S. large cap stocks
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	14	12
Pension Plans | Level 1 | Emerging markets
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	10	15
Pension Plans | Level 1 | U.S. investment grade bonds
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	17	13
Pension Plans | Level 1 | Cash equivalents
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	15	18
Pension Plans | Level 2
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	170	147
Pension Plans | Level 2 | U.S. large cap stocks
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	9	3
Pension Plans | Level 2 | U.S. small cap stocks
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	1	1
Pension Plans | Level 2 | Non-U.S. large cap stocks
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	23	18
Pension Plans | Level 2 | Emerging markets
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	15	14
Pension Plans | Level 2 | U.S. investment grade bonds
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	15	9
Pension Plans | Level 2 | U. S. high yield bonds
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	11	11
Pension Plans | Level 2 | Foreign government bonds and obligations
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	16	12
Pension Plans | Level 2 | Pooled pension funds
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	80	79
Pension Plans | Level 3
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	23	17
Pension Plans | Level 3 | Private real estate investment trust
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	11	8
Pension Plans | Level 3 | Hedge funds
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	12	9
Pension Plans | Total
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	362	327
Pension Plans | Total | U.S. large cap stocks
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	84	75
Pension Plans | Total | U.S. small cap stocks
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	39	34
Pension Plans | Total | Non-U.S. large cap stocks
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	37	30
Pension Plans | Total | Emerging markets
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	25	29
Pension Plans | Total | U.S. investment grade bonds
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	32	22
Pension Plans | Total | U. S. high yield bonds
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	11	11
Pension Plans | Total | Foreign government bonds and obligations
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	16	12
Pension Plans | Total | Private real estate investment trust
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	11	8
Pension Plans | Total | Hedge funds
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	12	9
Pension Plans | Total | Pooled pension funds
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	80	79
Pension Plans | Total | Cash equivalents
Defined Benefit Plan Disclosure
Fair Value of Plan Assets	$ 15	$ 18