Condensed Consolidated Statements of Earnings (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2017	Mar. 31, 2016
Income Statement [Abstract]
Revenues	$ 1,008.9	$ 688.8	$ 2,796.8	$ 1,922.5
Operating expenses:
Cost of revenues	773.7	486.5	2,199.5	1,389.6
Selling, general and administrative expenses	125.5	101.7	362.8	303.0
Total operating expenses	899.2	588.2	2,562.3	1,692.6
Operating income	109.7	100.6	234.6	229.9
Interest expense, net	10.8	6.5	31.8	19.2
Other non-operating (income) expenses, net	(7.4)	0.7	(0.8)	4.4
Earnings before income taxes	106.3	93.4	203.5	206.4
Provision for income taxes	30.4	29.7	63.8	68.9
Net earnings	$ 75.9	$ 63.7	$ 139.7	$ 137.4
Basic earnings per share (in dollars per share)	$ 0.64	$ 0.54	$ 1.18	$ 1.16
Diluted earnings per share (in dollars per share)	$ 0.63	$ 0.52	$ 1.15	$ 1.13
Weighted-average shares outstanding:
Basic (in shares)	117.8	118.2	118.3	118.3
Diluted (in shares)	120.7	121.7	121.3	121.8
Dividends declared per common share (in dollars per share)	$ 0.33	$ 0.30	$ 0.99	$ 0.9