Pension and Postretirement Benefit Plans - Components of net periodic benefit cost and other information 10Q (Details) - Funded - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Qualified and Non-qualified Pension Benefits | United States
Net periodic benefit cost (benefit)
Service cost	$ 67	$ 65	$ 134	$ 130
Interest cost	142	144	284	287
Expected return on plan assets	(259)	(261)	(518)	(521)
Amortization of prior service cost (benefit)	(6)	(6)	(12)	(12)
Amortization of net actuarial (gain) loss	97	88	194	176
Net periodic benefit cost (benefit) after settlements, curtailments, special termination benefits and other	41	30	82	60
Qualified and Non-qualified Pension Benefits | International
Net periodic benefit cost (benefit)
Service cost	34	34	67	67
Interest cost	37	43	74	86
Expected return on plan assets	(70)	(78)	(139)	(156)
Amortization of transition (asset) obligation		(1)		(1)
Amortization of prior service cost (benefit)	(3)	(4)	(6)	(7)
Amortization of net actuarial (gain) loss	30	23	60	45
Net periodic benefit cost (benefit) after settlements, curtailments, special termination benefits and other	28	17	56	34
Postretirement Benefits
Net periodic benefit cost (benefit)
Service cost	12	14	25	27
Interest cost	20	19	39	39
Expected return on plan assets	(21)	(22)	(42)	(45)
Amortization of prior service cost (benefit)	(13)	(14)	(26)	(28)
Amortization of net actuarial (gain) loss	14	15	28	31
Net periodic benefit cost (benefit) after settlements, curtailments, special termination benefits and other	$ 12	$ 12	$ 24	$ 24