CONSOLIDATED STATEMENTS OF OPERATIONS (UNAUDITED) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2018	Mar. 31, 2017
Income Statement [Abstract]
Revenue	$ 1,124,100	$ 1,086,418	$ 3,297,774	$ 3,217,228
Costs of revenue:
Direct costs	728,444	732,224	2,195,282	2,165,766
Indirect costs and selling expenses	273,145	269,237	788,569	780,397
Depreciation and amortization	17,717	17,703	53,563	53,898
Total costs of revenue	1,019,306	1,019,164	3,037,414	3,000,061
Income from operations	104,794	67,254	260,360	217,167
Interest expense and other, net	10,566	12,107	32,769	36,921
Income before income taxes	94,228	55,147	227,591	180,246
Income tax expense (benefit)	29,729	14,790	(21,749)	60,806
Net income	$ 64,499	$ 40,357	$ 249,340	$ 119,440
Basic earnings per share	$ 2.62	$ 1.65	$ 10.14	$ 4.90
Diluted earnings per share	$ 2.56	$ 1.61	$ 9.88	$ 4.77
Weighted-average basic shares outstanding	24,656	24,419	24,588	24,382
Weighted-average diluted shares outstanding	25,234	25,106	25,229	25,034