Pensions and Other Post-Retirement Benefits - Assets at Fair Value (Detail) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Pension Plans Postretirement And Other Employee Benefits [Line Items]
Total assets at fair value excluding NAV per share practical expedient	$ 1,152	$ 1,384
Total assets at fair value including NAV per share practical expedient	1,365	1,384	$ 1,574
Cash and equivalents
Pension Plans Postretirement And Other Employee Benefits [Line Items]
Total assets at fair value excluding NAV per share practical expedient	19	8
Equity securities - U.S.
Pension Plans Postretirement And Other Employee Benefits [Line Items]
Total assets at fair value excluding NAV per share practical expedient	64	92
Total assets at fair value including NAV per share practical expedient	26
Equity securities - Global
Pension Plans Postretirement And Other Employee Benefits [Line Items]
Total assets at fair value excluding NAV per share practical expedient	254	219
Total assets at fair value including NAV per share practical expedient	29
Equity securities – non-U.S.
Pension Plans Postretirement And Other Employee Benefits [Line Items]
Total assets at fair value excluding NAV per share practical expedient	89	192
Real estate
Pension Plans Postretirement And Other Employee Benefits [Line Items]
Total assets at fair value excluding NAV per share practical expedient	38	33
Total assets at fair value including NAV per share practical expedient	7
Corporate bonds
Pension Plans Postretirement And Other Employee Benefits [Line Items]
Total assets at fair value excluding NAV per share practical expedient	376	514
Total assets at fair value including NAV per share practical expedient	19
Debt issued by national, state or local government
Pension Plans Postretirement And Other Employee Benefits [Line Items]
Total assets at fair value excluding NAV per share practical expedient	181	182
Total assets at fair value including NAV per share practical expedient	2
Other
Pension Plans Postretirement And Other Employee Benefits [Line Items]
Total assets at fair value excluding NAV per share practical expedient	131	144
Cash
Pension Plans Postretirement And Other Employee Benefits [Line Items]
Total assets at fair value including NAV per share practical expedient	4
Liability driven investments
Pension Plans Postretirement And Other Employee Benefits [Line Items]
Total assets at fair value including NAV per share practical expedient	71
Private equity and hedge funds
Pension Plans Postretirement And Other Employee Benefits [Line Items]
Total assets at fair value including NAV per share practical expedient	54
Insurance and other
Pension Plans Postretirement And Other Employee Benefits [Line Items]
Total assets at fair value including NAV per share practical expedient	1
Level 1
Pension Plans Postretirement And Other Employee Benefits [Line Items]
Total assets at fair value excluding NAV per share practical expedient	273	219
Level 1 | Cash and equivalents
Pension Plans Postretirement And Other Employee Benefits [Line Items]
Total assets at fair value excluding NAV per share practical expedient	19	8
Level 1 | Equity securities - U.S.
Pension Plans Postretirement And Other Employee Benefits [Line Items]
Total assets at fair value excluding NAV per share practical expedient	53	25
Level 1 | Equity securities - Global
Pension Plans Postretirement And Other Employee Benefits [Line Items]
Total assets at fair value excluding NAV per share practical expedient	32	5
Level 1 | Equity securities – non-U.S.
Pension Plans Postretirement And Other Employee Benefits [Line Items]
Total assets at fair value excluding NAV per share practical expedient	6	23
Level 1 | Corporate bonds
Pension Plans Postretirement And Other Employee Benefits [Line Items]
Total assets at fair value excluding NAV per share practical expedient	127	104
Level 1 | Debt issued by national, state or local government
Pension Plans Postretirement And Other Employee Benefits [Line Items]
Total assets at fair value excluding NAV per share practical expedient	36	54
Level 2
Pension Plans Postretirement And Other Employee Benefits [Line Items]
Total assets at fair value excluding NAV per share practical expedient	712	1,002
Level 2 | Equity securities - U.S.
Pension Plans Postretirement And Other Employee Benefits [Line Items]
Total assets at fair value excluding NAV per share practical expedient	11	67
Level 2 | Equity securities - Global
Pension Plans Postretirement And Other Employee Benefits [Line Items]
Total assets at fair value excluding NAV per share practical expedient	222	214
Level 2 | Equity securities – non-U.S.
Pension Plans Postretirement And Other Employee Benefits [Line Items]
Total assets at fair value excluding NAV per share practical expedient	83	169
Level 2 | Corporate bonds
Pension Plans Postretirement And Other Employee Benefits [Line Items]
Total assets at fair value excluding NAV per share practical expedient	249	410
Level 2 | Debt issued by national, state or local government
Pension Plans Postretirement And Other Employee Benefits [Line Items]
Total assets at fair value excluding NAV per share practical expedient	145	128
Level 2 | Other
Pension Plans Postretirement And Other Employee Benefits [Line Items]
Total assets at fair value excluding NAV per share practical expedient	2	14
Level 3
Pension Plans Postretirement And Other Employee Benefits [Line Items]
Total assets at fair value excluding NAV per share practical expedient	167	163
Level 3 | Real estate
Pension Plans Postretirement And Other Employee Benefits [Line Items]
Total assets at fair value excluding NAV per share practical expedient	38	33
Level 3 | Other
Pension Plans Postretirement And Other Employee Benefits [Line Items]
Total assets at fair value excluding NAV per share practical expedient	$ 129	$ 130