QUARTERLY FINANCIAL DATA (UNAUDITED) - Schedule of Quarterly Condensed Financial Operating Results (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended									12 Months Ended
	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	[1]	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2016
Quarterly Financial Data [Abstract]
Revenue	$ 1,170,086	$ 1,124,100	$ 1,087,860		$ 1,085,814	$ 1,137,389	$ 1,086,418	$ 1,057,530	$ 1,073,280	$ 4,467,860	$ 4,354,617	$ 3,744,053
Income from operations	80,340	104,794	88,262		67,304	80,094	67,254	80,255	69,658	340,700	297,261	264,750
Net income	$ 51,831	$ 64,499	$ 142,795		$ 42,046	$ 44,231	$ 40,357	$ 42,420	$ 36,663	$ 301,171	$ 163,671	$ 142,799
Basic earnings per share	$ 2.10	$ 2.62	$ 5.80		$ 1.72	$ 1.81	$ 1.65	$ 1.74	$ 1.51	$ 12.23	$ 6.71	$ 5.89
Diluted earnings per share	$ 2.05	$ 2.56	$ 5.66		$ 1.67	$ 1.76	$ 1.61	$ 1.69	$ 1.47	$ 11.93	$ 6.53	$ 5.76
Weighted-average basic shares outstanding	24,700	24,656	24,622		24,487	24,459	24,419	24,387	24,340	24,616	24,401	24,262
Weighted-average diluted shares outstanding	25,331	25,234	25,211		25,243	25,172	25,106	25,069	24,928	25,255	25,069	24,802

[1] Net income for the second quarter of FY2018 includes a net benefit related to the TCJA. See Note 19.