CONSOLIDATED STATEMENTS OF OPERATIONS (UNAUDITED) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2021	Mar. 31, 2020
Income Statement [Abstract]
Revenue	$ 1,551,918	$ 1,465,600	$ 4,480,135	$ 4,224,461
Operating costs and expenses:
Costs of revenue	1,000,235	953,630	2,887,300	2,737,378
Indirect costs and selling expenses	369,015	371,135	1,071,826	1,081,175
Depreciation and amortization	31,230	27,159	93,608	81,888
Total operating costs and expenses	1,400,480	1,351,924	4,052,734	3,900,441
Income from operations	151,438	113,676	427,401	324,020
Interest expense and other, net	8,954	14,087	28,021	45,612
Income before income taxes	142,484	99,589	399,380	278,408
Income tax expense	22,140	19,012	78,914	50,659
Net income	$ 120,344	$ 80,577	$ 320,466	$ 227,749
Basic earnings per share	$ 4.83	$ 3.21	$ 12.81	$ 9.11
Diluted earnings per share	$ 4.78	$ 3.16	$ 12.66	$ 8.94
Weighted-average basic shares outstanding	24,935	25,078	25,026	25,012
Weighted-average diluted shares outstanding	25,166	25,478	25,307	25,481