Employee Benefits (Details 5) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Fair value of defined benefit plans assets by asset class
Fair value of defined benefit plans assets by asset class, Total	$ 2,088	$ 1,851
Level 1 [Member]
Fair value of defined benefit plans assets by asset class
Fair value of defined benefit plans assets by asset class, Total	722	650
Level 2 [Member]
Fair value of defined benefit plans assets by asset class
Fair value of defined benefit plans assets by asset class, Total	1,366	1,183
Level 3 [Member]
Fair value of defined benefit plans assets by asset class
Fair value of defined benefit plans assets by asset class, Total	0	18
Cash and short-term investments, and other [Member]
Fair value of defined benefit plans assets by asset class
Fair value of defined benefit plans assets by asset class, Total	68	180
Cash and short-term investments, and other [Member] | Level 1 [Member]
Fair value of defined benefit plans assets by asset class
Fair value of defined benefit plans assets by asset class, Total	20	2
Cash and short-term investments, and other [Member] | Level 2 [Member]
Fair value of defined benefit plans assets by asset class
Fair value of defined benefit plans assets by asset class, Total	48	178
Cash and short-term investments, and other [Member] | Level 3 [Member]
Fair value of defined benefit plans assets by asset class
Fair value of defined benefit plans assets by asset class, Total	0	0
US indexed equity securities [Member]
Fair value of defined benefit plans assets by asset class
Fair value of defined benefit plans assets by asset class, Total	514	399
US indexed equity securities [Member] | Level 1 [Member]
Fair value of defined benefit plans assets by asset class
Fair value of defined benefit plans assets by asset class, Total	145	119
US indexed equity securities [Member] | Level 2 [Member]
Fair value of defined benefit plans assets by asset class
Fair value of defined benefit plans assets by asset class, Total	369	280
US indexed equity securities [Member] | Level 3 [Member]
Fair value of defined benefit plans assets by asset class
Fair value of defined benefit plans assets by asset class, Total	0	0
US growth and value securities [Member]
Fair value of defined benefit plans assets by asset class
Fair value of defined benefit plans assets by asset class, Total	373	344
US growth and value securities [Member] | Level 1 [Member]
Fair value of defined benefit plans assets by asset class
Fair value of defined benefit plans assets by asset class, Total	325	307
US growth and value securities [Member] | Level 2 [Member]
Fair value of defined benefit plans assets by asset class
Fair value of defined benefit plans assets by asset class, Total	48	37
US growth and value securities [Member] | Level 3 [Member]
Fair value of defined benefit plans assets by asset class
Fair value of defined benefit plans assets by asset class, Total	0	0
UK equity securities [Member]
Fair value of defined benefit plans assets by asset class
Fair value of defined benefit plans assets by asset class, Total	183	154
UK equity securities [Member] | Level 1 [Member]
Fair value of defined benefit plans assets by asset class
Fair value of defined benefit plans assets by asset class, Total	101	85
UK equity securities [Member] | Level 2 [Member]
Fair value of defined benefit plans assets by asset class
Fair value of defined benefit plans assets by asset class, Total	82	69
UK equity securities [Member] | Level 3 [Member]
Fair value of defined benefit plans assets by asset class
Fair value of defined benefit plans assets by asset class, Total	0	0
International equity securities excluding UK [Member]
Fair value of defined benefit plans assets by asset class
Fair value of defined benefit plans assets by asset class, Total	227	225
International equity securities excluding UK [Member] | Level 1 [Member]
Fair value of defined benefit plans assets by asset class
Fair value of defined benefit plans assets by asset class, Total	131	137
International equity securities excluding UK [Member] | Level 2 [Member]
Fair value of defined benefit plans assets by asset class
Fair value of defined benefit plans assets by asset class, Total	96	87
International equity securities excluding UK [Member] | Level 3 [Member]
Fair value of defined benefit plans assets by asset class
Fair value of defined benefit plans assets by asset class, Total	0	1
Long duration bonds [Member]
Fair value of defined benefit plans assets by asset class
Fair value of defined benefit plans assets by asset class, Total	517	370
Long duration bonds [Member] | Level 1 [Member]
Fair value of defined benefit plans assets by asset class
Fair value of defined benefit plans assets by asset class, Total	0	0
Long duration bonds [Member] | Level 2 [Member]
Fair value of defined benefit plans assets by asset class
Fair value of defined benefit plans assets by asset class, Total	517	370
Long duration bonds [Member] | Level 3 [Member]
Fair value of defined benefit plans assets by asset class
Fair value of defined benefit plans assets by asset class, Total	0	0
Intermediate Duration Securities [Member]
Fair value of defined benefit plans assets by asset class
Fair value of defined benefit plans assets by asset class, Total	11	3
Intermediate Duration Securities [Member] | Level 1 [Member]
Fair value of defined benefit plans assets by asset class
Fair value of defined benefit plans assets by asset class, Total	0	0
Intermediate Duration Securities [Member] | Level 2 [Member]
Fair value of defined benefit plans assets by asset class
Fair value of defined benefit plans assets by asset class, Total	11	3
Intermediate Duration Securities [Member] | Level 3 [Member]
Fair value of defined benefit plans assets by asset class
Fair value of defined benefit plans assets by asset class, Total	0	0
Agency mortgage backed securities
Fair value of defined benefit plans assets by asset class
Fair value of defined benefit plans assets by asset class, Total	7	13
Agency mortgage backed securities | Level 1 [Member]
Fair value of defined benefit plans assets by asset class
Fair value of defined benefit plans assets by asset class, Total	0	0
Agency mortgage backed securities | Level 2 [Member]
Fair value of defined benefit plans assets by asset class
Fair value of defined benefit plans assets by asset class, Total	7	13
Agency mortgage backed securities | Level 3 [Member]
Fair value of defined benefit plans assets by asset class
Fair value of defined benefit plans assets by asset class, Total	0	0
Asset-backed Securities [Member]
Fair value of defined benefit plans assets by asset class
Fair value of defined benefit plans assets by asset class, Total	16	10
Asset-backed Securities [Member] | Level 1 [Member]
Fair value of defined benefit plans assets by asset class
Fair value of defined benefit plans assets by asset class, Total	0	0
Asset-backed Securities [Member] | Level 2 [Member]
Fair value of defined benefit plans assets by asset class
Fair value of defined benefit plans assets by asset class, Total	16	10
Asset-backed Securities [Member] | Level 3 [Member]
Fair value of defined benefit plans assets by asset class
Fair value of defined benefit plans assets by asset class, Total	0	0
Non-agency mortgage backed securities [Member]
Fair value of defined benefit plans assets by asset class
Fair value of defined benefit plans assets by asset class, Total	45	52
Non-agency mortgage backed securities [Member] | Level 1 [Member]
Fair value of defined benefit plans assets by asset class
Fair value of defined benefit plans assets by asset class, Total	0	0
Non-agency mortgage backed securities [Member] | Level 2 [Member]
Fair value of defined benefit plans assets by asset class
Fair value of defined benefit plans assets by asset class, Total	45	52
Non-agency mortgage backed securities [Member] | Level 3 [Member]
Fair value of defined benefit plans assets by asset class
Fair value of defined benefit plans assets by asset class, Total	0	0
UK fixed income securities [Member]
Fair value of defined benefit plans assets by asset class
Fair value of defined benefit plans assets by asset class, Total	66	41
UK fixed income securities [Member] | Level 1 [Member]
Fair value of defined benefit plans assets by asset class
Fair value of defined benefit plans assets by asset class, Total	0	0
UK fixed income securities [Member] | Level 2 [Member]
Fair value of defined benefit plans assets by asset class
Fair value of defined benefit plans assets by asset class, Total	66	41
UK fixed income securities [Member] | Level 3 [Member]
Fair value of defined benefit plans assets by asset class
Fair value of defined benefit plans assets by asset class, Total	0	0
International fixed income securities excluding UK [Member]
Fair value of defined benefit plans assets by asset class
Fair value of defined benefit plans assets by asset class, Total	61	43
International fixed income securities excluding UK [Member] | Level 1 [Member]
Fair value of defined benefit plans assets by asset class
Fair value of defined benefit plans assets by asset class, Total	0	0
International fixed income securities excluding UK [Member] | Level 2 [Member]
Fair value of defined benefit plans assets by asset class
Fair value of defined benefit plans assets by asset class, Total	61	43
International fixed income securities excluding UK [Member] | Level 3 [Member]
Fair value of defined benefit plans assets by asset class
Fair value of defined benefit plans assets by asset class, Total	0	0
Real estate UK [Member]
Fair value of defined benefit plans assets by asset class
Fair value of defined benefit plans assets by asset class, Total		17
Real estate UK [Member] | Level 1 [Member]
Fair value of defined benefit plans assets by asset class
Fair value of defined benefit plans assets by asset class, Total		0
Real estate UK [Member] | Level 2 [Member]
Fair value of defined benefit plans assets by asset class
Fair value of defined benefit plans assets by asset class, Total		0
Real estate UK [Member] | Level 3 [Member]
Fair value of defined benefit plans assets by asset class
Fair value of defined benefit plans assets by asset class, Total		$ 17