BUSINESS SEGMENTS AND FOREIGN OPERATIONS, Segment Information (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Jun. 30, 2014 Segment	Jun. 30, 2013	Jun. 30, 2012
BUSINESS SEGMENTS AND FOREIGN OPERATIONS [Abstract]
Number of reportable segments	2
Segment Reporting Information [Line Items]
Net sales	$ 263,909	$ 285,282	$ 355,870
Interest income	121	102	95
Interest expense	936	1,435	1,475
Income taxes	4,226	4,986	17,815
Depreciation and amortization	10,657	10,838	10,756
Net earnings attributable to Twin Disc	3,644	3,882	26,743
Assets	266,985	285,458
Expenditures for segment assets	7,245	6,582	13,733
Reportable Segment [Member]
Segment Reporting Information [Line Items]
Net sales	348,979	375,952	454,585
Interest income	333	498	727
Interest expense	2,610	3,310	3,862
Income taxes	7,665	6,742	21,904
Depreciation and amortization	9,115	9,314	9,244
Net earnings attributable to Twin Disc	13,314	15,981	36,768
Assets	311,885	315,582	330,373
Expenditures for segment assets	6,744	6,054	12,979
Reportable Segment [Member] | Manufacturing [Member]
Segment Reporting Information [Line Items]
Net sales	227,590	245,592	325,174
Interest income	311	479	688
Interest expense	2,565	3,248	3,798
Income taxes	6,233	5,112	19,444
Depreciation and amortization	8,566	8,817	8,373
Net earnings attributable to Twin Disc	7,029	10,141	29,572
Assets	254,652	258,617	272,098
Expenditures for segment assets	6,429	5,705	11,821
Reportable Segment [Member] | Distribution [Member]
Segment Reporting Information [Line Items]
Net sales	121,389	130,360	129,411
Interest income	22	19	39
Interest expense	45	62	64
Income taxes	1,432	1,630	2,460
Depreciation and amortization	549	497	871
Net earnings attributable to Twin Disc	6,285	5,840	7,196
Assets	57,233	56,965	58,275
Expenditures for segment assets	315	349	1,158
Intra-segment Sales [Member]
Segment Reporting Information [Line Items]
Net sales	28,342	31,267	23,861
Intra-segment Sales [Member] | Manufacturing [Member]
Segment Reporting Information [Line Items]
Net sales	18,416	16,140	16,189
Intra-segment Sales [Member] | Distribution [Member]
Segment Reporting Information [Line Items]
Net sales	9,926	15,127	7,672
Inter-segment Sales [Member]
Segment Reporting Information [Line Items]
Net sales	56,728	59,403	74,854
Inter-segment Sales [Member] | Manufacturing [Member]
Segment Reporting Information [Line Items]
Net sales	53,960	55,746	71,134
Inter-segment Sales [Member] | Distribution [Member]
Segment Reporting Information [Line Items]
Net sales	$ 2,768	$ 3,657	$ 3,720