Note K - Business Segments and Foreign Operations - Segment Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Net Sales	$ 246,838	$ 302,663
Intra-segment sales	27,119	34,410
Inter-segment sales	49,432	49,836
Interest income	78	43
Interest expense	1,860	1,927
Income taxes	(4,169)	3,711
Depreciation and amortization	11,925	9,335
Net (loss) income attributable to Twin Disc	(39,817)	10,673
Assets	294,127	346,870
Expenditures for segment assets	10,699	11,979
Manufacturing Segment [Member]
Intra-segment sales	14,230	20,384
Inter-segment sales	43,854	46,078
Distribution Segment [Member]
Intra-segment sales	12,889	14,026
Inter-segment sales	5,578	3,758
Operating Segments [Member]
Net Sales	323,389	386,909
Interest income	368	1,180
Interest expense	2,128	3,049
Income taxes	(1,759)	8,292
Depreciation and amortization	11,530	13,295
Net (loss) income attributable to Twin Disc	(31,050)	25,310
Assets	408,535	430,688
Expenditures for segment assets	10,349	11,388
Interest expense		3,049
Operating Segments [Member] | Manufacturing Segment [Member]
Net Sales	227,565	280,428
Interest income	346	1,154
Interest expense	2,128
Income taxes	(2,027)	7,939
Depreciation and amortization	11,151	12,893
Net (loss) income attributable to Twin Disc	(31,603)	25,062
Assets	365,417	384,612
Expenditures for segment assets	9,615	10,725
Interest expense		3,086
Operating Segments [Member] | Distribution Segment [Member]
Net Sales	95,824	106,481
Interest income	22	26
Interest expense
Income taxes	268	353
Depreciation and amortization	379	402
Net (loss) income attributable to Twin Disc	553	248
Assets	43,118	46,076
Expenditures for segment assets	$ 734	663
Interest expense		$ (37)