INCOME TAXES - Schedule of Deferred Tax Assets and Liabilities (Detail 3) - USD ($) $ in Thousands	Jun. 30, 2018	Jun. 30, 2017
Deferred tax assets:
Deferred compensation and post-retirement obligations	$ 27,842	$ 37,257
Reserves and accruals	30,180	40,058
Stock-based compensation	7,793	13,599
Deferred rent	3,750	6,091
Other		2,000
Total deferred tax assets	69,565	99,005
Deferred tax liabilities:
Goodwill and other intangible assets	(238,020)	(337,849)
Unbilled revenue	(17,363)	(20,913)
Prepaid expenses	(3,991)	(4,554)
Interest rate swap	(3,701)	(963)
Other	(7,370)	(8,046)
Total deferred tax liabilities	(270,445)	(372,325)
Net deferred tax liability	$ (200,880)	$ (273,320)