Retirement Plans (Tables)

6 Months Ended

Nov. 30, 2015

Retirement Plan (Tables) [Abstract]

Schedule of Retirement Plan Costs

	Three Months Ended				Six Months Ended
	2015		2014		2015		2014
Defined benefit pension plans	$	54	$	(10)	$	107	$	(17)
Defined contribution plans		103		94		205		188
Postretirement healthcare plans		20		20		41		40
	$	177	$	104	$	353	$	211

Schedule of Net Periodic Benefit Cost

		Three Months Ended				Six Months Ended
Pension Plans		2015		2014		2015		2014
	Service cost	$	165	$	164	$	331	$	328
	Interest cost		295		275		590		550
	Expected return on plan assets		(377)		(420)		(754)		(840)
	Amortization of prior service credit		(29)		(29)		(60)		(55)
		$	54	$	(10)	$	107	$	(17)
		Three Months Ended				Six Months Ended
Postretirement Healthcare Plans		2015		2014		2015		2014
	Service cost	$	10	$	10	$	20	$	20
	Interest cost		10		10		21		20
		$	20	$	20	$	41	$	40

Schedule of Pension Plans Contributions

	2015		2014
Required	$	8	$	247
Voluntary		322		83
	$	330	$	330