INCOME TAXES - Income Tax Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2018
Income Tax Disclosure [Abstract]
Expected statutory rate	26.50%	26.50%	26.50%
Expected provision for income taxes	$ 91,479	$ 116,752	$ 102,323
Effect of foreign tax rate differences	218	(1,344)	2,352
Change in valuation allowance	(222)	(5,045)	1,779
Amortization of deferred charges	0	0	4,242
Effect of permanent differences	1,215	(577)	4,332
Effect of changes in unrecognized tax benefits	(19,284)	31,992	5,543
Effect of withholding taxes	8,036	2,097	7,927
Difference in tax filings from provision	933	(250)	1,321
Effect of U.S. tax reform	0	0	19,037
Effect of tax credits for research and development	(14,947)	(13,550)	(3,875)
Effect of accrual for undistributed earnings	4,233	(13,112)	(1,154)
Effect of US BEAT	41,207	16,030	0
Effect of CARES Act	(7,009)	0	0
Other Items	4,527	5,473	(1)
Impact of internal reorganization of subsidiaries	451	16,471	0
Provision for (recovery of) income taxes	$ 110,837	$ 154,937	$ 143,826