Pension and Postretirement Benefit Plans (Tables)

3 Months Ended

Mar. 31, 2016

Pension and Postretirement Benefit Plans

Components of net periodic benefit cost (benefit)

	Three months ended March 31,
	Qualified and Non-qualified
	Pension Benefits								Postretirement
	United States				International				Benefits
(Millions)	2016		2015		2016		2015		2016		2015
Net periodic benefit cost (benefit)
Service cost	$	65	$	73	$	33	$	42	$	13	$	21
Interest cost		143		164		43		55		20		25
Expected return on plan assets		(260)		(267)		(78)		(81)		(23)		(22)
Amortization of transition (asset) obligation		—		—		—		—		—		—
Amortization of prior service cost (benefit)		(6)		(6)		(3)		(4)		(14)		(8)
Amortization of net actuarial (gain) loss		88		102		22		38		16		19
Net periodic benefit cost (benefit)	$	30	$	66	$	17	$	50	$	12	$	35
Settlements, curtailments, special termination benefits and other		—		—		—		(17)		—		—
Net periodic benefit cost (benefit) after settlements, curtailments, special termination benefits and other	$	30	$	66	$	17	$	33	$	12	$	35

Discount rates using spot yield curve approach

	U.S. Qualified Pension		International Pension (weighted average)		U.S. Postretirement Medical
December 31, 2015 Liability:
Benefit obligation	4.47	%	3.12	%	4.32	%
2016 Net Periodic Benefit Cost Components:
Service cost	4.72	%	2.84	%	4.60	%
Interest cost	3.77	%	2.72	%	3.44	%