Employee Benefits (Plan's Assets Measured At Fair Value On A Recurring Basis) (Details) (USD $)	Dec. 31, 2012	Dec. 31, 2011
Defined Benefit Plan Disclosure [Line Items]
Total assets carried at fair value	$ 1,075,000,000	$ 928,000,000
U.S. Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Domestic large cap equity	144,000,000	129,000,000
Domestic small cap equity	16,000,000	14,000,000
Developed international equities	80,000,000	62,000,000
Emerging markets equity	42,000,000	28,000,000
Investment grade fixed-income	390,000,000	311,000,000
High yield fixed-income	32,000,000	26,000,000
Real estate investment trusts	24,000,000	23,000,000
Alternative investments (commingled fund)	5,000,000	5,000,000
Alternative investments (fund of funds)	14,000,000	14,000,000
Private equity	2,000,000	2,000,000
Cash	10,000,000	6,000,000
Total U.S. Pension Plan	759,000,000	620,000,000
U.K. Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Developed international equities	30,000,000	24,000,000
U.K. fixed-income	177,000,000	187,000,000
Emerging market index	9,000,000	8,000,000
Alternative investments	39,000,000	32,000,000
Total U.K. pension plan	255,000,000	251,000,000
Other Non-U.S. Pension Plans (Excluding U.K.) [Member]
Defined Benefit Plan Disclosure [Line Items]
Insurance group annuity contracts	61,000,000	57,000,000
Total Other Non-U.S. Pension Plans (Excluding U.K.)	61,000,000	57,000,000
Quoted Market Prices In Active Markets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets carried at fair value	0	0
Quoted Market Prices In Active Markets (Level 1) [Member] | U.S. Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Domestic large cap equity		0
Domestic small cap equity		0
Developed international equities		0
Emerging markets equity		0
Investment grade fixed-income		0
High yield fixed-income		0
Real estate investment trusts		0
Alternative investments (commingled fund)		0
Alternative investments (fund of funds)		0
Private equity		0
Cash		0
Total U.S. Pension Plan	0	0
Quoted Market Prices In Active Markets (Level 1) [Member] | U.K. Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Developed international equities		0
U.K. fixed-income		0
Emerging market index		0
Alternative investments		0
Total U.K. pension plan	0	0
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		0
Total Other Non-U.S. Pension Plans (Excluding U.K.)	0	0
Pricing Methods With Significant Observable Market Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets carried at fair value	954,000,000	818,000,000
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	144,000,000	129,000,000
Domestic small cap equity	16,000,000	14,000,000
Developed international equities	80,000,000	62,000,000
Emerging markets equity	42,000,000	28,000,000
Investment grade fixed-income	390,000,000	311,000,000
High yield fixed-income	32,000,000	26,000,000
Real estate investment trusts	24,000,000	23,000,000
Alternative investments (commingled fund)	0	0
Alternative investments (fund of funds)	0	0
Private equity	0	0
Cash	10,000,000	6,000,000
Total U.S. Pension Plan	738,000,000	599,000,000
Pricing Methods With Significant Observable Market Inputs (Level 2) [Member] | U.K. Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Developed international equities	30,000,000	24,000,000
U.K. fixed-income	177,000,000	187,000,000
Emerging market index	9,000,000	8,000,000
Alternative investments	0	0
Total U.K. pension plan	216,000,000	219,000,000
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]
Insurance group annuity contracts	0	0
Total Other Non-U.S. Pension Plans (Excluding U.K.)	0	0
Pricing Methods With Significant Unobservable Market Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets carried at fair value	121,000,000	110,000,000
Pricing Methods With Significant Unobservable Market Inputs (Level 3) [Member] | U.S. Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Domestic large cap equity		0
Domestic small cap equity		0
Developed international equities		0
Emerging markets equity		0
Investment grade fixed-income		0
High yield fixed-income		0
Real estate investment trusts		0
Alternative investments (commingled fund)	5,000,000	5,000,000
Alternative investments (fund of funds)	14,000,000	14,000,000
Private equity	2,000,000	2,000,000
Cash	0	0
Total U.S. Pension Plan	21,000,000	21,000,000
Pricing Methods With Significant Unobservable Market Inputs (Level 3) [Member] | U.K. Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Developed international equities	0	0
U.K. fixed-income	0	0
Emerging market index	0	0
Alternative investments	39,000,000	32,000,000
Total U.K. pension plan	39,000,000	32,000,000
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	61,000,000	57,000,000
Total Other Non-U.S. Pension Plans (Excluding U.K.)	$ 61,000,000	$ 57,000,000