Retirement Plans (Tables)

6 Months Ended

Nov. 30, 2017

Retirement Plan Tables [Abstract]

Schedule of Retirement Plan Costs

Our retirement plans costs for the periods ended November 30 were as follows (in millions):

	Three Months Ended				Six Months Ended
	2017		2016		2017		2016
Defined benefit pension plans	$	37	$	58	$	74	$	116
Defined contribution plans		124		112		251		231
Postretirement healthcare plans		18		19		37		38
	$	179	$	189	$	362	$	385

Schedule of Net Periodic Benefit Cost

Net periodic benefit cost of the pension and postretirement healthcare plans for the periods ended November 30 included the following components (in millions):

	Three Months Ended
	U.S. Pension Plans						International Pension Plans						Postretirement Healthcare Plans
	2017			2016			2017			2016			2017		2016
Service cost	$	170		$	160		$	23		$	20		$	9	$	9
Interest cost		278			282			13			11			9		10
Expected return on plan assets		(406	)		(375	)		(11	)		(11	)		—		—
Amortization of prior service credit and other		(29	)		(30	)		(1	)		1			—		—
	$	13		$	37		$	24		$	21		$	18	$	19
	Six Months Ended
	U.S. Pension Plans						International Pension Plans						Postretirement Healthcare Plans
	2017			2016			2017			2016			2017		2016
Service cost	$	340		$	319		$	46		$	41		$	18	$	18
Interest cost		557			564			25			22			19		20
Expected return on plan assets		(812	)		(751	)		(22	)		(21	)		—		—
Amortization of prior service credit and other		(59	)		(59	)		(1	)		1			—		—
	$	26		$	73		$	48		$	43		$	37	$	38

Schedule of Tax Qualified Pension Plans Contributions

Contributions to our tax-qualified U.S. domestic pension plans for the six-month periods ended November 30 were as follows (in millions):

	2017		2016
Required	$	268	$	250
Voluntary		482		250
	$	750	$	500