Employee Benefits (Plan's Assets Measured At Fair Value On A Recurring Basis) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
U.S. Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Domestic large cap equity	$ 129	$ 120
Domestic small cap equity	14	15
Developed international equities	62	67
Emerging markets equity	28	38
Investment grade fixed-income	311	308
High yield fixed-income	26	31
Real estate investment trusts	23	21
Alternative investments (commingled fund)	5	5
Alternative investments (fund of funds)	14	14
Private equity	2	2
Cash	6	9
Total U.S. Pension Plan	620	630
U.K. Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Developed international equities	24	33
U.K. fixed-income	187	144
Emerging market index	8	8
Alternative investments	32	33
Total U.K. pension plan	251	218
Other Non-U.S. Pension Plans (Excluding U.K.) [Member]
Defined Benefit Plan Disclosure [Line Items]
Insurance group annuity contracts	57	36
Total Other Non-U.S. Pension Plans (Excluding U.K.)	57	36
Total assets carried at fair value	928	884
Quoted Market Prices In Active Markets (Level 1) [Member] | U.S. Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Domestic large cap equity
Domestic small cap equity
Developed international equities
Emerging markets equity
Investment grade fixed-income
High yield fixed-income
Real estate investment trusts
Alternative investments (commingled fund)
Alternative investments (fund of funds)
Private equity
Cash
Total U.S. Pension Plan
Quoted Market Prices In Active Markets (Level 1) [Member] | U.K. Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Developed international equities
U.K. fixed-income
Emerging market index
Alternative investments
Total U.K. pension plan
Quoted Market Prices In Active Markets (Level 1) [Member] | Other Non-U.S. Pension Plans (Excluding U.K.) [Member]
Defined Benefit Plan Disclosure [Line Items]
Insurance group annuity contracts
Total Other Non-U.S. Pension Plans (Excluding U.K.)
Total assets carried at fair value
Pricing Methods With Significant Observable Market Inputs (Level 2) [Member] | U.S. Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Domestic large cap equity	129	120
Domestic small cap equity	14	15
Developed international equities	62	67
Emerging markets equity	28	38
Investment grade fixed-income	311	308
High yield fixed-income	26	31
Real estate investment trusts	23	21
Cash	6	9
Total U.S. Pension Plan	599	609
Pricing Methods With Significant Observable Market Inputs (Level 2) [Member] | U.K. Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Developed international equities	24	33
U.K. fixed-income	187	144
Emerging market index	8	8
Total U.K. pension plan	219	185
Pricing Methods With Significant Observable Market Inputs (Level 2) [Member] | Other Non-U.S. Pension Plans (Excluding U.K.) [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets carried at fair value	818	794
Pricing Methods With Significant Unobservable Market Inputs (Level 3) [Member] | U.S. Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Alternative investments (commingled fund)	5	5
Alternative investments (fund of funds)	14	14
Private equity	2	2
Total U.S. Pension Plan	21	21
Pricing Methods With Significant Unobservable Market Inputs (Level 3) [Member] | U.K. Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Alternative investments	32	33
Total U.K. pension plan	32	33
Pricing Methods With Significant Unobservable Market Inputs (Level 3) [Member] | Other Non-U.S. Pension Plans (Excluding U.K.) [Member]
Defined Benefit Plan Disclosure [Line Items]
Insurance group annuity contracts	57	36
Total Other Non-U.S. Pension Plans (Excluding U.K.)	57	36
Total assets carried at fair value	$ 110	$ 90