Comprehensive (Loss) Income (Details) (USD $) In Thousands	3 Months Ended
	Sep. 30, 2011	Sep. 30, 2010
Equity and Comprehensive (Loss) Income [Abstract]
Net income	$ 73,573	$ 35,956
Unrealized loss on derivatives designated and qualified as cash flow hedges, net of income tax benefit of $6.6 million and $2.2 million, respectively	(10,745)	(3,593)
Reclassification of unrealized loss on expired derivatives designated and qualified as cash flow hedges, net of income tax benefit of $0.2 million and $0.0 million, respectively	309	46
Unrecognized net pension and other postretirement benefit gains (loss), net of income tax expense (benefit) of $0.3 million and ($0.6) million, respectively	848	(2,186)
Reclassification of net pension and other postretirement benefit loss, net of income tax benefit of $0.7 million and $1.0 million, respectively	1,287	1,861
Foreign currency translation adjustments, net of income tax (benefit) expense of ($13.0) million and $51.9 million, respectively	(69,877)	74,251
Total comprehensive (loss) income	(4,605)	106,335
Comprehensive (loss) income attributable to noncontrolling interests	(114)	2,544
Comprehensive (loss) income attributable to Kennametal Shareowners	$ (4,491)	$ 103,791