Segment Data - Sales and Operating (Loss) Income by Segment (Details) - USD ($) $ in Thousands	3 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Jun. 30, 2020
Segment Reporting Information [Line Items]
Assets	$ 2,558,996		$ 3,037,591
External sales:
Sales	400,305	$ 518,088
Operating (loss) income:
Total operating (loss) income	(17,178)	16,376
Interest expense	10,578	7,881
Other income, net	(4,019)	(2,681)
(Loss) income from continuing operations before income taxes	(23,737)	11,176
Infrastructure [Member]
External sales:
Sales	152,429	194,003
Operating (loss) income:
Total operating (loss) income	(7,268)	2,690
Corporate [Member]
Operating (loss) income:
Total operating (loss) income	820	240
Metal Cutting
External sales:
Sales	247,876	324,085
Operating (loss) income:
Total operating (loss) income	$ 23,626	$ (19,306)