Pension and Postretirement Benefit Plans - Components of net periodic benefit cost and other information 10Q (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
United States Qualified and Non-qualified Pension Benefits
Net periodic benefit cost (benefit)
Service cost	$ 65	$ 73	$ 130	$ 146
Interest cost	144	164	287	328
Expected return on plan assets	(261)	(267)	(521)	(534)
Amortization of prior service cost (benefit)	(6)	(6)	(12)	(12)
Amortization of net actuarial (gain) loss	88	102	176	204
Net periodic benefit cost (benefit) after settlements, curtailments, special termination benefits and other	30	66	60	132
International Qualified and Non-qualified Pension Benefits
Net periodic benefit cost (benefit)
Service cost	34	40	67	82
Interest cost	43	55	86	110
Expected return on plan assets	(78)	(81)	(156)	(162)
Amortization of transition (asset) obligation	(1)	(1)	(1)	(1)
Amortization of prior service cost (benefit)	(4)	(3)	(7)	(7)
Amortization of net actuarial (gain) loss	23	38	45	76
Settlements, curtailments, special terminations and other				(17)
Net periodic benefit cost (benefit) after settlements, curtailments, special termination benefits and other	17	48	34	81
Postretirement Benefits
Net periodic benefit cost (benefit)
Service cost	14	22	27	43
Interest cost	19	25	39	50
Expected return on plan assets	(22)	(23)	(45)	(45)
Amortization of prior service cost (benefit)	(14)	(8)	(28)	(16)
Amortization of net actuarial (gain) loss	15	19	31	38
Net periodic benefit cost (benefit) after settlements, curtailments, special termination benefits and other	$ 12	$ 35	$ 24	$ 70