Condensed Consolidated Statements of Earnings - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2023	Dec. 31, 2022
Income Statement [Abstract]
Revenues	$ 1,405.0	$ 1,292.9	$ 2,836.0	$ 2,576.2
Operating expenses:
Cost of revenues	1,057.2	988.2	2,132.5	1,978.7
Selling, general and administrative expenses	223.4	196.8	430.8	402.1
Total operating expenses	1,280.6	1,185.0	2,563.2	2,380.8
Operating income	124.4	107.9	272.8	195.4
Interest expense, net	(36.3)	(34.1)	(69.7)	(61.0)
Other non-operating expenses, net	(0.4)	(1.9)	(2.6)	(7.1)
Earnings before income taxes	87.6	71.9	200.5	127.3
Provision for income taxes	17.4	14.4	39.4	19.3
Net earnings	$ 70.3	$ 57.5	$ 161.2	$ 108.0
Basic earnings per share (in dollars per share)	$ 0.60	$ 0.49	$ 1.37	$ 0.92
Diluted earnings per share (in dollars per share)	$ 0.59	$ 0.48	$ 1.35	$ 0.91
Weighted-average shares outstanding:
Basic (in shares)	117.7	117.7	117.8	117.6
Diluted (in shares)	119.1	118.9	119.1	118.9