Employee Benefit Plans (Fair values of pension and post retirement plan assets by asset category) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	$ 6,113	$ 5,553
Pension Benefits | Cash equivalents and other
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	179	195
Pension Benefits | U.S. equity: | Large Cap
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	1,220	1,031
Pension Benefits | U.S. equity: | Other
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	514	524
Pension Benefits | Non-U.S. equity: | Large Cap
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	308	381
Pension Benefits | Non-U.S. equity: | Other
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	391	395
Pension Benefits | Common/collective trust funds
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	1,387	0
Pension Benefits | Fixed Income: | Corporate debt instruments
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	494	1,053
Pension Benefits | Fixed Income: | U.S. Treasury securities and agency debentures
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	231	635
Pension Benefits | Fixed Income: | State and municipal
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	176	72
Pension Benefits | Fixed Income: | Other
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	57	48
Pension Benefits | Real estate: | REITs
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	32	29
Pension Benefits | Real estate: | Partnerships
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	227	321
Pension Benefits | Other alternative investments: | Private equity
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	530	456
Pension Benefits | Other alternative investments: | Debt
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	180	192
Pension Benefits | Other alternative investments: | Hedge funds
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	187	221
Pension Benefits | Level 1
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	2,639	2,286
Pension Benefits | Level 1 | Cash equivalents and other
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	53	0
Pension Benefits | Level 1 | U.S. equity: | Large Cap
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	1,220	927
Pension Benefits | Level 1 | U.S. equity: | Other
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	514	425
Pension Benefits | Level 1 | Non-U.S. equity: | Large Cap
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	308	313
Pension Benefits | Level 1 | Non-U.S. equity: | Other
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	391	228
Pension Benefits | Level 1 | Common/collective trust funds
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	0	0
Pension Benefits | Level 1 | Fixed Income: | Corporate debt instruments
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	43	27
Pension Benefits | Level 1 | Fixed Income: | U.S. Treasury securities and agency debentures
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	2	331
Pension Benefits | Level 1 | Fixed Income: | State and municipal
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	69	1
Pension Benefits | Level 1 | Fixed Income: | Other
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	7	5
Pension Benefits | Level 1 | Real estate: | REITs
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	32	29
Pension Benefits | Level 1 | Real estate: | Partnerships
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	0	0
Pension Benefits | Level 1 | Other alternative investments: | Private equity
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	0	0
Pension Benefits | Level 1 | Other alternative investments: | Debt
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	0	0
Pension Benefits | Level 1 | Other alternative investments: | Hedge funds
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	0	0
Pension Benefits | Level 2
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	2,350	2,077
Pension Benefits | Level 2 | Cash equivalents and other
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	126	195
Pension Benefits | Level 2 | U.S. equity: | Large Cap
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	0	104
Pension Benefits | Level 2 | U.S. equity: | Other
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	0	99
Pension Benefits | Level 2 | Non-U.S. equity: | Large Cap
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	0	68
Pension Benefits | Level 2 | Non-U.S. equity: | Other
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	0	167
Pension Benefits | Level 2 | Common/collective trust funds
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	1,387	0
Pension Benefits | Level 2 | Fixed Income: | Corporate debt instruments
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	451	1,026
Pension Benefits | Level 2 | Fixed Income: | U.S. Treasury securities and agency debentures
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	229	304
Pension Benefits | Level 2 | Fixed Income: | State and municipal
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	107	71
Pension Benefits | Level 2 | Fixed Income: | Other
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	50	43
Pension Benefits | Level 2 | Real estate: | REITs
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	0	0
Pension Benefits | Level 2 | Real estate: | Partnerships
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	0	0
Pension Benefits | Level 2 | Other alternative investments: | Private equity
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	0	0
Pension Benefits | Level 2 | Other alternative investments: | Debt
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	0	0
Pension Benefits | Level 2 | Other alternative investments: | Hedge funds
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	0	0
Pension Benefits | Level 3
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	1,124	1,190
Pension Benefits | Level 3 | Cash equivalents and other
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	0	0
Pension Benefits | Level 3 | U.S. equity: | Large Cap
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	0	0
Pension Benefits | Level 3 | U.S. equity: | Other
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	0	0
Pension Benefits | Level 3 | Non-U.S. equity: | Large Cap
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	0	0
Pension Benefits | Level 3 | Non-U.S. equity: | Other
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	0	0
Pension Benefits | Level 3 | Common/collective trust funds
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	0	0
Pension Benefits | Level 3 | Fixed Income: | Corporate debt instruments
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	0	0
Pension Benefits | Level 3 | Fixed Income: | U.S. Treasury securities and agency debentures
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	0	0
Pension Benefits | Level 3 | Fixed Income: | State and municipal
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	0	0
Pension Benefits | Level 3 | Fixed Income: | Other
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	0	0
Pension Benefits | Level 3 | Real estate: | REITs
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	0	0
Pension Benefits | Level 3 | Real estate: | Partnerships
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	227	321
Pension Benefits | Level 3 | Other alternative investments: | Private equity
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	530	456
Pension Benefits | Level 3 | Other alternative investments: | Debt
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	180	192
Pension Benefits | Level 3 | Other alternative investments: | Hedge funds
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	187	221
Other Postretirement Plans
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	1,315	1,156
Other Postretirement Plans | Cash equivalents and other
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	17	13
Other Postretirement Plans | U.S. equity: | Large Cap
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	472	383
Other Postretirement Plans | U.S. equity: | Other
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	26	66
Other Postretirement Plans | Non-U.S. equity: | Large Cap
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	111	96
Other Postretirement Plans | Non-U.S. equity: | Other
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	20	19
Other Postretirement Plans | Common/collective trust funds
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	502	0
Other Postretirement Plans | Fixed Income: | Corporate debt instruments
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	25	161
Other Postretirement Plans | Fixed Income: | U.S. Treasury securities and agency debentures
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	12	282
Other Postretirement Plans | Fixed Income: | State and municipal
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	9	9
Other Postretirement Plans | Fixed Income: | Other
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	3	2
Other Postretirement Plans | Real estate: | REITs
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	2	1
Other Postretirement Plans | Real estate: | Partnerships
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	19	24
Other Postretirement Plans | Other alternative investments: | Private equity
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	60	58
Other Postretirement Plans | Other alternative investments: | Debt
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	27	31
Other Postretirement Plans | Other alternative investments: | Hedge funds
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	10	11
Other Postretirement Plans | Level 1
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	640	521
Other Postretirement Plans | Level 1 | Cash equivalents and other
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	3	0
Other Postretirement Plans | Level 1 | U.S. equity: | Large Cap
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	472	378
Other Postretirement Plans | Level 1 | U.S. equity: | Other
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	26	21
Other Postretirement Plans | Level 1 | Non-U.S. equity: | Large Cap
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	111	93
Other Postretirement Plans | Level 1 | Non-U.S. equity: | Other
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	20	11
Other Postretirement Plans | Level 1 | Common/collective trust funds
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	0	0
Other Postretirement Plans | Level 1 | Fixed Income: | Corporate debt instruments
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	2	1
Other Postretirement Plans | Level 1 | Fixed Income: | U.S. Treasury securities and agency debentures
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	0	16
Other Postretirement Plans | Level 1 | Fixed Income: | State and municipal
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	4	0
Other Postretirement Plans | Level 1 | Fixed Income: | Other
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	0	0
Other Postretirement Plans | Level 1 | Real estate: | REITs
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	2	1
Other Postretirement Plans | Level 1 | Real estate: | Partnerships
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	0	0
Other Postretirement Plans | Level 1 | Other alternative investments: | Private equity
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	0	0
Other Postretirement Plans | Level 1 | Other alternative investments: | Debt
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	0	0
Other Postretirement Plans | Level 1 | Other alternative investments: | Hedge funds
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	0	0
Other Postretirement Plans | Level 2
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	559	511
Other Postretirement Plans | Level 2 | Cash equivalents and other
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	14	13
Other Postretirement Plans | Level 2 | U.S. equity: | Large Cap
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	0	5
Other Postretirement Plans | Level 2 | U.S. equity: | Other
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	0	45
Other Postretirement Plans | Level 2 | Non-U.S. equity: | Large Cap
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	0	3
Other Postretirement Plans | Level 2 | Non-U.S. equity: | Other
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	0	8
Other Postretirement Plans | Level 2 | Common/collective trust funds
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	502	0
Other Postretirement Plans | Level 2 | Fixed Income: | Corporate debt instruments
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	23	160
Other Postretirement Plans | Level 2 | Fixed Income: | U.S. Treasury securities and agency debentures
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	12	266
Other Postretirement Plans | Level 2 | Fixed Income: | State and municipal
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	5	9
Other Postretirement Plans | Level 2 | Fixed Income: | Other
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	3	2
Other Postretirement Plans | Level 2 | Real estate: | REITs
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	0	0
Other Postretirement Plans | Level 2 | Real estate: | Partnerships
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	0	0
Other Postretirement Plans | Level 2 | Other alternative investments: | Private equity
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	0	0
Other Postretirement Plans | Level 2 | Other alternative investments: | Debt
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	0	0
Other Postretirement Plans | Level 2 | Other alternative investments: | Hedge funds
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	0	0
Other Postretirement Plans | Level 3
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	116	124
Other Postretirement Plans | Level 3 | Cash equivalents and other
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	0	0
Other Postretirement Plans | Level 3 | U.S. equity: | Large Cap
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	0	0
Other Postretirement Plans | Level 3 | U.S. equity: | Other
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	0	0
Other Postretirement Plans | Level 3 | Non-U.S. equity: | Large Cap
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	0	0
Other Postretirement Plans | Level 3 | Non-U.S. equity: | Other
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	0	0
Other Postretirement Plans | Level 3 | Common/collective trust funds
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	0	0
Other Postretirement Plans | Level 3 | Fixed Income: | Corporate debt instruments
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	0	0
Other Postretirement Plans | Level 3 | Fixed Income: | U.S. Treasury securities and agency debentures
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	0	0
Other Postretirement Plans | Level 3 | Fixed Income: | State and municipal
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	0	0
Other Postretirement Plans | Level 3 | Fixed Income: | Other
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	0	0
Other Postretirement Plans | Level 3 | Real estate: | REITs
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	0	0
Other Postretirement Plans | Level 3 | Real estate: | Partnerships
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	19	24
Other Postretirement Plans | Level 3 | Other alternative investments: | Private equity
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	60	58
Other Postretirement Plans | Level 3 | Other alternative investments: | Debt
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	27	31
Other Postretirement Plans | Level 3 | Other alternative investments: | Hedge funds
Defined Benefit Plan Disclosure [Line Items]
Pension plan assets by asset category	$ 10	$ 11