CONSOLIDATED STATEMENTS OF OPERATIONS (UNAUDITED) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2020	Dec. 31, 2019
Income Statement [Abstract]
Revenue	$ 1,468,711	$ 1,395,469	$ 2,928,217	$ 2,758,861
Operating costs and expenses:
Costs of revenue	947,131	904,867	1,887,065	1,783,748
Indirect costs and selling expenses	347,807	352,448	702,811	710,040
Depreciation and amortization	32,234	27,967	62,378	54,729
Total operating costs and expenses	1,327,172	1,285,282	2,652,254	2,548,517
Income from operations	141,539	110,187	275,963	210,344
Interest expense and other, net	9,087	14,714	19,067	31,525
Income before income taxes	132,452	95,473	256,896	178,819
Income tax expense	25,974	16,278	56,774	31,647
Net income	$ 106,478	$ 79,195	$ 200,122	$ 147,172
Basic earnings per share	$ 4.22	$ 3.16	$ 7.95	$ 5.89
Diluted earnings per share	$ 4.18	$ 3.11	$ 7.86	$ 5.78
Weighted-average basic shares outstanding	25,225	25,065	25,162	24,979
Weighted-average diluted shares outstanding	25,451	25,435	25,469	25,483