Goodwill and Other Intangible Assets - Carrying Amount of Goodwill Attributable to Each Segment (Details) - USD ($) $ in Thousands	3 Months Ended
	Sep. 30, 2017	Jun. 30, 2017
Goodwill [Line Items]
Goodwill, Foreign Currency Translation Gain (Loss)	$ 3,311
Goodwill [Roll Forward]
Goodwill	1,088,731	$ 1,085,420
Accumulated impairment losses	(784,053)	(784,053)
Goodwill, Beginning Balance	301,367
Goodwill, Ending Balance	304,678
Industrial [Member]
Goodwill [Line Items]
Goodwill, Foreign Currency Translation Gain (Loss)	3,176
Goodwill [Roll Forward]
Goodwill	413,870	410,694
Accumulated impairment losses	(137,204)	(137,204)
Goodwill, Beginning Balance	273,490
Goodwill, Ending Balance	276,666
Infrastructure [Member]
Goodwill [Line Items]
Goodwill, Foreign Currency Translation Gain (Loss)	0
Goodwill [Roll Forward]
Goodwill	633,211	633,211
Accumulated impairment losses	(633,211)	(633,211)
Goodwill, Beginning Balance	0
Goodwill, Ending Balance	0
WIDIA [Member]
Goodwill [Line Items]
Goodwill, Foreign Currency Translation Gain (Loss)	135
Goodwill [Roll Forward]
Goodwill	41,650	41,515
Accumulated impairment losses	(13,638)	$ (13,638)
Goodwill, Beginning Balance	27,877
Goodwill, Ending Balance	$ 28,012