Pension and Postretirement Benefit Plans - Components of net periodic benefit cost and other information 10Q (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
United States Qualified and Non-qualified Pension Benefits
Net periodic benefit cost (benefit)
Service cost	$ 64	$ 73	$ 194	$ 219
Interest cost	144	163	431	491
Expected return on plan assets	(261)	(267)	(782)	(801)
Amortization of prior service cost (benefit)	(6)	(6)	(18)	(18)
Amortization of net actuarial (gain) loss	89	101	265	305
Net periodic benefit cost (benefit) after settlements, curtailments, special termination benefits and other	30	64	90	196
International Qualified and Non-qualified Pension Benefits
Net periodic benefit cost (benefit)
Service cost	35	36	102	118
Interest cost	45	49	131	159
Expected return on plan assets	(78)	(74)	(234)	(236)
Amortization of transition (asset) obligation			(1)	(1)
Amortization of prior service cost (benefit)	(3)	(3)	(10)	(10)
Amortization of net actuarial (gain) loss	21	34	66	110
Settlements, curtailments, special terminations and other				(17)
Net periodic benefit cost (benefit) after settlements, curtailments, special termination benefits and other	20	42	54	123
Postretirement Benefits
Net periodic benefit cost (benefit)
Service cost	13	19	40	62
Interest cost	20	25	59	75
Expected return on plan assets	(23)	(23)	(68)	(68)
Amortization of prior service cost (benefit)	(13)	(10)	(41)	(26)
Amortization of net actuarial (gain) loss	15	18	46	56
Net periodic benefit cost (benefit) after settlements, curtailments, special termination benefits and other	$ 12	$ 29	$ 36	$ 99