BUSINESS SEGMENTS - Summarized Financial Information of Reportable Segments (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2018
Segment Reporting Information [Line Items]
Revenue from external customers	$ 1,564,000	$ 1,551,918	$ 1,468,711	$ 1,459,506	$ 1,495,581	$ 1,465,600	$ 1,395,469	$ 1,363,392	$ 6,044,135	$ 5,720,042	$ 4,986,341
Net income	136,977	$ 120,344	$ 106,478	$ 93,644	93,731	$ 80,577	$ 79,195	$ 67,977	457,443	321,480	265,604
Net assets	2,665,278				2,661,310				2,665,278	2,661,310	2,371,466	$ 2,106,887
Goodwill	3,632,578				3,407,110				3,632,578	3,407,110	3,336,079
Total long-term assets	4,841,196				4,456,586				4,841,196	4,456,586	4,055,323
Total assets	6,172,372				5,542,472				6,172,372	5,542,472	5,086,843
Capital expenditures									73,129	72,303	47,902
Depreciation and amortization									125,363	110,688	85,877
Domestic Operations
Segment Reporting Information [Line Items]
Revenue from external customers									5,868,392	5,556,672	4,829,450
Net income									432,912	302,822	249,793
Net assets	2,461,048				2,482,283				2,461,048	2,482,283	2,206,109
Goodwill	3,491,747				3,279,856				3,491,747	3,279,856	3,224,685
Total long-term assets	4,665,782				4,297,885				4,665,782	4,297,885	3,927,783
Total assets	5,898,869				5,293,588				5,898,869	5,293,588	4,876,399
Capital expenditures									69,610	70,499	46,406
Depreciation and amortization									121,725	105,874	81,205
International Operations
Segment Reporting Information [Line Items]
Revenue from external customers									175,743	163,370	156,891
Net income									24,531	18,658	15,811
Net assets	204,230				179,027				204,230	179,027	165,357
Goodwill	140,831				127,254				140,831	127,254	111,394
Total long-term assets	175,414				158,701				175,414	158,701	127,540
Total assets	$ 273,503				$ 248,884				273,503	248,884	210,444
Capital expenditures									3,519	1,804	1,496
Depreciation and amortization									$ 3,638	$ 4,814	$ 4,672