Retirement Plans and Profit Sharing Arrangements (Assets Measured at Fair Value) (Details 6) (Pension Plans [Member], USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Pension plan assets measured at fair value on a recurring basis
Defined Benefit Plan, Fair Value of Plan Assets	$ 612	$ 544	$ 437
Actual return on plan assets:
Fair value of plan assets at the end of the year	612	544	437
Real estate investment trusts [Member]
Pension plan assets measured at fair value on a recurring basis
Defined Benefit Plan, Fair Value of Plan Assets	14	2	12
Summary of changes in Level 3 assets measured at fair value on a recurring basis
Fair value of plan assets at the beginning of the year	2	12	11
Actual return on plan assets:
Relating to assets still held at the reporting date	1
Purchases	11	2	1
Sales		(12)
Fair value of plan assets at the end of the year	14	2	12
Hedge funds [Member]
Pension plan assets measured at fair value on a recurring basis
Defined Benefit Plan, Fair Value of Plan Assets	21	20	18
Summary of changes in Level 3 assets measured at fair value on a recurring basis
Fair value of plan assets at the beginning of the year	20	18	12
Actual return on plan assets:
Relating to assets still held at the reporting date	1	2	1
Purchases			5
Fair value of plan assets at the end of the year	21	20	18
Level 1 [Member]
Pension plan assets measured at fair value on a recurring basis
Defined Benefit Plan, Fair Value of Plan Assets	215	245
Actual return on plan assets:
Fair value of plan assets at the end of the year	215	245
Level 1 [Member] | U.S. large cap stocks [Member]
Pension plan assets measured at fair value on a recurring basis
Defined Benefit Plan, Fair Value of Plan Assets	74	97
Actual return on plan assets:
Fair value of plan assets at the end of the year	74	97
Level 1 [Member] | U.S. small cap stocks [Member]
Pension plan assets measured at fair value on a recurring basis
Defined Benefit Plan, Fair Value of Plan Assets	59	55
Actual return on plan assets:
Fair value of plan assets at the end of the year	59	55
Level 1 [Member] | Non-U.S. large cap stocks [Member]
Pension plan assets measured at fair value on a recurring basis
Defined Benefit Plan, Fair Value of Plan Assets	21	21
Actual return on plan assets:
Fair value of plan assets at the end of the year	21	21
Level 1 [Member] | Non US small cap stock [Member]
Pension plan assets measured at fair value on a recurring basis
Defined Benefit Plan, Fair Value of Plan Assets	18	21
Actual return on plan assets:
Fair value of plan assets at the end of the year	18	21
Level 1 [Member] | Emerging markets [Member]
Pension plan assets measured at fair value on a recurring basis
Defined Benefit Plan, Fair Value of Plan Assets	15	14
Actual return on plan assets:
Fair value of plan assets at the end of the year	15	14
Level 1 [Member] | U.S. investment grade bonds [Member]
Pension plan assets measured at fair value on a recurring basis
Defined Benefit Plan, Fair Value of Plan Assets	19	17
Actual return on plan assets:
Fair value of plan assets at the end of the year	19	17
Level 1 [Member] | Cash equivalents [Member]
Pension plan assets measured at fair value on a recurring basis
Defined Benefit Plan, Fair Value of Plan Assets	9	20
Actual return on plan assets:
Fair value of plan assets at the end of the year	9	20
Level 2 [Member]
Pension plan assets measured at fair value on a recurring basis
Defined Benefit Plan, Fair Value of Plan Assets	362	277
Actual return on plan assets:
Fair value of plan assets at the end of the year	362	277
Level 2 [Member] | U.S. large cap stocks [Member]
Pension plan assets measured at fair value on a recurring basis
Defined Benefit Plan, Fair Value of Plan Assets	84	43
Actual return on plan assets:
Fair value of plan assets at the end of the year	84	43
Level 2 [Member] | U.S. small cap stocks [Member]
Pension plan assets measured at fair value on a recurring basis
Defined Benefit Plan, Fair Value of Plan Assets	1	1
Actual return on plan assets:
Fair value of plan assets at the end of the year	1	1
Level 2 [Member] | Non-U.S. large cap stocks [Member]
Pension plan assets measured at fair value on a recurring basis
Defined Benefit Plan, Fair Value of Plan Assets	33	35
Actual return on plan assets:
Fair value of plan assets at the end of the year	33	35
Level 2 [Member] | Non US small cap stock [Member]
Pension plan assets measured at fair value on a recurring basis
Defined Benefit Plan, Fair Value of Plan Assets	0
Actual return on plan assets:
Fair value of plan assets at the end of the year	0
Level 2 [Member] | Emerging markets [Member]
Pension plan assets measured at fair value on a recurring basis
Defined Benefit Plan, Fair Value of Plan Assets	24	23
Actual return on plan assets:
Fair value of plan assets at the end of the year	24	23
Level 2 [Member] | U.S. investment grade bonds [Member]
Pension plan assets measured at fair value on a recurring basis
Defined Benefit Plan, Fair Value of Plan Assets	15	14
Actual return on plan assets:
Fair value of plan assets at the end of the year	15	14
Level 2 [Member] | U.S. high yield bonds [Member]
Pension plan assets measured at fair value on a recurring basis
Defined Benefit Plan, Fair Value of Plan Assets	27	21
Actual return on plan assets:
Fair value of plan assets at the end of the year	27	21
Level 2 [Member] | Non-U.S. investment grade bonds [Member]
Pension plan assets measured at fair value on a recurring basis
Defined Benefit Plan, Fair Value of Plan Assets	15	14
Actual return on plan assets:
Fair value of plan assets at the end of the year	15	14
Level 2 [Member] | Pooled pension funds [Member]
Pension plan assets measured at fair value on a recurring basis
Defined Benefit Plan, Fair Value of Plan Assets	144	126
Actual return on plan assets:
Fair value of plan assets at the end of the year	144	126
Level 2 [Member] | AVC assets [Member]
Pension plan assets measured at fair value on a recurring basis
Defined Benefit Plan, Fair Value of Plan Assets	19
Actual return on plan assets:
Fair value of plan assets at the end of the year	19
Level 3 [Member]
Pension plan assets measured at fair value on a recurring basis
Defined Benefit Plan, Fair Value of Plan Assets	35	22
Actual return on plan assets:
Fair value of plan assets at the end of the year	35	22
Level 3 [Member] | Real estate investment trusts [Member]
Pension plan assets measured at fair value on a recurring basis
Defined Benefit Plan, Fair Value of Plan Assets	14	2
Actual return on plan assets:
Fair value of plan assets at the end of the year	14	2
Level 3 [Member] | Hedge funds [Member]
Pension plan assets measured at fair value on a recurring basis
Defined Benefit Plan, Fair Value of Plan Assets	21	20
Actual return on plan assets:
Fair value of plan assets at the end of the year	21	20
Total [Member]
Pension plan assets measured at fair value on a recurring basis
Defined Benefit Plan, Fair Value of Plan Assets	612	544
Actual return on plan assets:
Fair value of plan assets at the end of the year	612	544
Total [Member] | U.S. large cap stocks [Member]
Pension plan assets measured at fair value on a recurring basis
Defined Benefit Plan, Fair Value of Plan Assets	158	140
Actual return on plan assets:
Fair value of plan assets at the end of the year	158	140
Total [Member] | U.S. small cap stocks [Member]
Pension plan assets measured at fair value on a recurring basis
Defined Benefit Plan, Fair Value of Plan Assets	60	56
Actual return on plan assets:
Fair value of plan assets at the end of the year	60	56
Total [Member] | Non-U.S. large cap stocks [Member]
Pension plan assets measured at fair value on a recurring basis
Defined Benefit Plan, Fair Value of Plan Assets	54	56
Actual return on plan assets:
Fair value of plan assets at the end of the year	54	56
Total [Member] | Non US small cap stock [Member]
Pension plan assets measured at fair value on a recurring basis
Defined Benefit Plan, Fair Value of Plan Assets	18	21
Actual return on plan assets:
Fair value of plan assets at the end of the year	18	21
Total [Member] | Emerging markets [Member]
Pension plan assets measured at fair value on a recurring basis
Defined Benefit Plan, Fair Value of Plan Assets	39	37
Actual return on plan assets:
Fair value of plan assets at the end of the year	39	37
Total [Member] | U.S. investment grade bonds [Member]
Pension plan assets measured at fair value on a recurring basis
Defined Benefit Plan, Fair Value of Plan Assets	34	31
Actual return on plan assets:
Fair value of plan assets at the end of the year	34	31
Total [Member] | U.S. high yield bonds [Member]
Pension plan assets measured at fair value on a recurring basis
Defined Benefit Plan, Fair Value of Plan Assets	27	21
Actual return on plan assets:
Fair value of plan assets at the end of the year	27	21
Total [Member] | Non-U.S. investment grade bonds [Member]
Pension plan assets measured at fair value on a recurring basis
Defined Benefit Plan, Fair Value of Plan Assets	15	14
Actual return on plan assets:
Fair value of plan assets at the end of the year	15	14
Total [Member] | Real estate investment trusts [Member]
Pension plan assets measured at fair value on a recurring basis
Defined Benefit Plan, Fair Value of Plan Assets	14	2
Actual return on plan assets:
Fair value of plan assets at the end of the year	14	2
Total [Member] | Hedge funds [Member]
Pension plan assets measured at fair value on a recurring basis
Defined Benefit Plan, Fair Value of Plan Assets	21	20
Actual return on plan assets:
Fair value of plan assets at the end of the year	21	20
Total [Member] | Pooled pension funds [Member]
Pension plan assets measured at fair value on a recurring basis
Defined Benefit Plan, Fair Value of Plan Assets	144	126
Actual return on plan assets:
Fair value of plan assets at the end of the year	144	126
Total [Member] | AVC assets [Member]
Pension plan assets measured at fair value on a recurring basis
Defined Benefit Plan, Fair Value of Plan Assets	19
Actual return on plan assets:
Fair value of plan assets at the end of the year	19
Total [Member] | Cash equivalents [Member]
Pension plan assets measured at fair value on a recurring basis
Defined Benefit Plan, Fair Value of Plan Assets	9	20
Actual return on plan assets:
Fair value of plan assets at the end of the year	$ 9	$ 20