CONSOLIDATED STATEMENTS OF OPERATIONS (UNAUDITED) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2019	Mar. 31, 2018
Income Statement [Abstract]
Revenue	$ 1,264,958	$ 1,124,100	$ 3,612,463	$ 3,297,774
Costs of revenue:
Direct costs	824,024	728,444	2,397,633	2,195,282
Indirect costs and selling expenses	324,828	273,145	859,262	788,569
Depreciation and amortization	21,198	17,717	58,797	53,563
Total costs of revenue	1,170,050	1,019,306	3,315,692	3,037,414
Income from operations	94,908	104,794	296,771	260,360
Interest expense and other, net	13,466	10,566	31,773	32,769
Income before income taxes	81,442	94,228	264,998	227,591
Income tax expense (benefit)	13,297	29,729	49,424	(21,749)
Net income	$ 68,145	$ 64,499	$ 215,574	$ 249,340
Basic earnings per share	$ 2.74	$ 2.62	$ 8.69	$ 10.14
Diluted earnings per share	$ 2.69	$ 2.56	$ 8.50	$ 9.88
Weighted-average basic shares outstanding	24,866	24,656	24,819	24,588
Weighted-average diluted shares outstanding	25,348	25,234	25,369	25,229