Goodwill and Other Intangible Assets Schedule of Goodwill (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Dec. 31, 2015	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2016
Goodwill [Line Items]
Goodwill, Gross		$ 1,085,855	$ 1,085,420	$ 1,082,540
Goodwill, Accumulated Impairment Loss		(784,053)	(784,053)	(784,053)
Goodwill		301,802	301,367	298,487
Goodwill, Period Increase (Decrease)		435	2,880
Industrial [Member]
Goodwill [Line Items]
Goodwill, Gross		411,458	410,694	408,705
Goodwill, Accumulated Impairment Loss		137,204	137,204	137,204
Goodwill		274,254	273,490	271,501
Goodwill, Written off Related to Sale of Business Unit				(1,100)
Goodwill, Period Increase (Decrease)		764	1,989
WIDIA [Member]
Goodwill [Line Items]
Goodwill, Gross		41,186	41,515	40,624
Goodwill, Accumulated Impairment Loss		13,638	13,638	13,638
Goodwill		27,548	27,877	26,986
Goodwill, Period Increase (Decrease)		(329)	891
Infrastructure [Member]
Goodwill [Line Items]
Goodwill, Gross		633,211	633,211	633,211
Goodwill, Accumulated Impairment Loss		633,211	633,211	633,211
Goodwill		0	0	0
Goodwill, Written off Related to Sale of Business Unit				$ (6,500)
Goodwill, Period Increase (Decrease)		$ 0	$ 0
Goodwill, Impairment Loss	$ 105,700