Pension and Other Postretirement Employee Benefit Plans - Plan Assets and Liabilities Measured At Fair Value (Details) - USD ($)	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Defined benefit pension plans
Pension and OPEB plan assets and liabilities - supplemental information
Unfunded commitments to purchase limited partnership investments for the plan	$ 735,000,000	$ 895,000,000
Excluded amount of US receivables for investments sold and dividends and interest receivables	130,000,000	74,000,000
Excluded amount of other liabilities	21,000,000	17,000,000
U.S. defined benefit pension plans
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	14,272,000,000	14,125,000,000	$ 14,623,000,000
Pension and OPEB plan assets and liabilities - supplemental information
Excluded amount of payables for investments purchased	203,000,000	106,000,000
U.S. defined benefit pension plans | Level 3
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	396,000,000	539,000,000	351,000,000	$ 441,000,000
U.S. defined benefit pension plans | Total assets measured at fair value(e)
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	10,341,000,000	10,139,000,000
U.S. defined benefit pension plans | Total assets measured at fair value(e) | Level 1
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	7,819,000,000	7,670,000,000
U.S. defined benefit pension plans | Total assets measured at fair value(e) | Level 2
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	2,126,000,000	1,930,000,000
U.S. defined benefit pension plans | Total assets measured at fair value(e) | Level 3
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	396,000,000	539,000,000
U.S. defined benefit pension plans | Cash and cash equivalents
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	74,000,000	112,000,000
U.S. defined benefit pension plans | Cash and cash equivalents | Level 1
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	74,000,000	112,000,000
U.S. defined benefit pension plans | Cash and cash equivalents | Level 2
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	0	0
U.S. defined benefit pension plans | Cash and cash equivalents | Level 3
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	0	0
U.S. defined benefit pension plans | Equity securities
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	5,192,000,000	4,833,000,000
U.S. defined benefit pension plans | Equity securities | Level 1
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	5,178,000,000	4,826,000,000
U.S. defined benefit pension plans | Equity securities | Level 2
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	12,000,000	5,000,000
U.S. defined benefit pension plans | Equity securities | Level 3
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	2,000,000	2,000,000	4,000,000	4,000,000
U.S. defined benefit pension plans | Common/collective trust funds
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	266,000,000	339,000,000
U.S. defined benefit pension plans | Common/collective trust funds | Level 1
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	266,000,000	339,000,000
U.S. defined benefit pension plans | Common/collective trust funds | Level 2
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	0	0
U.S. defined benefit pension plans | Common/collective trust funds | Level 3
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	0	0
U.S. defined benefit pension plans | Limited partnerships
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	62,000,000	53,000,000
U.S. defined benefit pension plans | Limited partnerships | Level 1
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	62,000,000	53,000,000
U.S. defined benefit pension plans | Limited partnerships | Level 2
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	0	0
U.S. defined benefit pension plans | Limited partnerships | Level 3
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	0	0
U.S. defined benefit pension plans | Corporate debt securities
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	1,795,000,000	1,621,000,000
U.S. defined benefit pension plans | Corporate debt securities | Level 1
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	0	0
U.S. defined benefit pension plans | Corporate debt securities | Level 2
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	1,791,000,000	1,619,000,000
U.S. defined benefit pension plans | Corporate debt securities | Level 3
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	4,000,000	2,000,000	9,000,000	7,000,000
U.S. defined benefit pension plans | U.S. federal, state, local and non-U.S. government debt securities
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	1,160,000,000	688,000,000
U.S. defined benefit pension plans | U.S. federal, state, local and non-U.S. government debt securities | Level 1
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	926,000,000	580,000,000
U.S. defined benefit pension plans | U.S. federal, state, local and non-U.S. government debt securities | Level 2
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	234,000,000	108,000,000
U.S. defined benefit pension plans | U.S. federal, state, local and non-U.S. government debt securities | Level 3
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	0	0
U.S. defined benefit pension plans | Mortgage-backed securities
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	104,000,000	68,000,000
U.S. defined benefit pension plans | Mortgage-backed securities | Level 1
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	39,000,000	0
U.S. defined benefit pension plans | Mortgage-backed securities | Level 2
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	65,000,000	67,000,000
U.S. defined benefit pension plans | Mortgage-backed securities | Level 3
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	0	1,000,000	1,000,000	0
U.S. defined benefit pension plans | Derivative receivables
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	24,000,000	104,000,000
U.S. defined benefit pension plans | Derivative receivables | Level 1
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	0	0
U.S. defined benefit pension plans | Derivative receivables | Level 2
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	24,000,000	104,000,000
U.S. defined benefit pension plans | Derivative receivables | Level 3
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	0	0
U.S. defined benefit pension plans | Other
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	1,664,000,000	2,321,000,000
U.S. defined benefit pension plans | Other | Level 1
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	1,274,000,000	1,760,000,000
U.S. defined benefit pension plans | Other | Level 2
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	0	27,000,000
U.S. defined benefit pension plans | Other | Level 3
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	390,000,000	534,000,000	337,000,000	430,000,000
U.S. defined benefit pension plans | Certain limited partnerships and common/collective trust funds
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	4,000,000,000	4,100,000,000
U.S. defined benefit pension plans | Total liabilities measured at fair value
Pension and OPEB plan assets and liabilities measured at fair value
Plan liabilities measured at fair value	(14,000,000)	(35,000,000)
U.S. defined benefit pension plans | Total liabilities measured at fair value | Level 1
Pension and OPEB plan assets and liabilities measured at fair value
Plan liabilities measured at fair value	0	0
U.S. defined benefit pension plans | Total liabilities measured at fair value | Level 2
Pension and OPEB plan assets and liabilities measured at fair value
Plan liabilities measured at fair value	(14,000,000)	(35,000,000)
U.S. defined benefit pension plans | Total liabilities measured at fair value | Level 3
Pension and OPEB plan assets and liabilities measured at fair value
Plan liabilities measured at fair value	0	0
U.S. defined benefit pension plans | Derivative payables
Pension and OPEB plan assets and liabilities measured at fair value
Plan liabilities measured at fair value	(14,000,000)	(35,000,000)
U.S. defined benefit pension plans | Derivative payables | Level 1
Pension and OPEB plan assets and liabilities measured at fair value
Plan liabilities measured at fair value	0	0
U.S. defined benefit pension plans | Derivative payables | Level 2
Pension and OPEB plan assets and liabilities measured at fair value
Plan liabilities measured at fair value	(14,000,000)	(35,000,000)
U.S. defined benefit pension plans | Derivative payables | Level 3
Pension and OPEB plan assets and liabilities measured at fair value
Plan liabilities measured at fair value	0	0
Non-U.S. defined benefit pension plans
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	3,431,000,000	3,511,000,000	3,718,000,000
Non-U.S. defined benefit pension plans | Level 3
Pension and OPEB plan assets and liabilities - supplemental information
Fair value of plan assets and liabilities	0	0
Non-U.S. defined benefit pension plans | Total assets measured at fair value(e)
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	3,382,000,000	3,430,000,000
Non-U.S. defined benefit pension plans | Total assets measured at fair value(e) | Level 1
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	1,659,000,000	1,722,000,000
Non-U.S. defined benefit pension plans | Total assets measured at fair value(e) | Level 2
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	1,723,000,000	1,708,000,000
Non-U.S. defined benefit pension plans | Cash and cash equivalents
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	124,000,000	115,000,000
Non-U.S. defined benefit pension plans | Cash and cash equivalents | Level 1
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	122,000,000	114,000,000
Non-U.S. defined benefit pension plans | Cash and cash equivalents | Level 2
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	2,000,000	1,000,000
Non-U.S. defined benefit pension plans | Equity securities
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	1,134,000,000	1,159,000,000
Non-U.S. defined benefit pension plans | Equity securities | Level 1
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	980,000,000	1,002,000,000
Non-U.S. defined benefit pension plans | Equity securities | Level 2
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	154,000,000	157,000,000
Non-U.S. defined benefit pension plans | Common/collective trust funds
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	118,000,000	135,000,000
Non-U.S. defined benefit pension plans | Common/collective trust funds | Level 1
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	118,000,000	135,000,000
Non-U.S. defined benefit pension plans | Common/collective trust funds | Level 2
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	0	0
Non-U.S. defined benefit pension plans | Limited partnerships
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	0	0
Non-U.S. defined benefit pension plans | Limited partnerships | Level 1
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	0	0
Non-U.S. defined benefit pension plans | Limited partnerships | Level 2
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	0	0
Non-U.S. defined benefit pension plans | Corporate debt securities
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	715,000,000	758,000,000
Non-U.S. defined benefit pension plans | Corporate debt securities | Level 1
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	0	0
Non-U.S. defined benefit pension plans | Corporate debt securities | Level 2
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	715,000,000	758,000,000
Non-U.S. defined benefit pension plans | U.S. federal, state, local and non-U.S. government debt securities
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	783,000,000	716,000,000
Non-U.S. defined benefit pension plans | U.S. federal, state, local and non-U.S. government debt securities | Level 1
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	213,000,000	212,000,000
Non-U.S. defined benefit pension plans | U.S. federal, state, local and non-U.S. government debt securities | Level 2
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	570,000,000	504,000,000
Non-U.S. defined benefit pension plans | Mortgage-backed securities
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	13,000,000	28,000,000
Non-U.S. defined benefit pension plans | Mortgage-backed securities | Level 1
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	3,000,000	2,000,000
Non-U.S. defined benefit pension plans | Mortgage-backed securities | Level 2
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	10,000,000	26,000,000
Non-U.S. defined benefit pension plans | Derivative receivables
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	219,000,000	209,000,000
Non-U.S. defined benefit pension plans | Derivative receivables | Level 1
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	0	0
Non-U.S. defined benefit pension plans | Derivative receivables | Level 2
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	219,000,000	209,000,000
Non-U.S. defined benefit pension plans | Other
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	276,000,000	310,000,000
Non-U.S. defined benefit pension plans | Other | Level 1
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	223,000,000	257,000,000
Non-U.S. defined benefit pension plans | Other | Level 2
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	53,000,000	53,000,000
Non-U.S. defined benefit pension plans | Certain limited partnerships and common/collective trust funds
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	243,000,000	234,000,000
Non-U.S. defined benefit pension plans | Total liabilities measured at fair value
Pension and OPEB plan assets and liabilities measured at fair value
Plan liabilities measured at fair value	(194,000,000)	(153,000,000)
Non-U.S. defined benefit pension plans | Total liabilities measured at fair value | Level 1
Pension and OPEB plan assets and liabilities measured at fair value
Plan liabilities measured at fair value	0	0
Non-U.S. defined benefit pension plans | Total liabilities measured at fair value | Level 2
Pension and OPEB plan assets and liabilities measured at fair value
Plan liabilities measured at fair value	(194,000,000)	(153,000,000)
Non-U.S. defined benefit pension plans | Derivative payables
Pension and OPEB plan assets and liabilities measured at fair value
Plan liabilities measured at fair value	(194,000,000)	(153,000,000)
Non-U.S. defined benefit pension plans | Derivative payables | Level 1
Pension and OPEB plan assets and liabilities measured at fair value
Plan liabilities measured at fair value	0	0
Non-U.S. defined benefit pension plans | Derivative payables | Level 2
Pension and OPEB plan assets and liabilities measured at fair value
Plan liabilities measured at fair value	(194,000,000)	(153,000,000)
OPEB plans
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	1,956,000,000	1,855,000,000	1,903,000,000
OPEB plans | Level 3
Pension and OPEB plan assets and liabilities measured at fair value
Plan assets measured at fair value	$ 1,957,000,000	$ 1,855,000,000	$ 1,903,000,000	$ 1,749,000,000