Earnings Per Share - Computation of Basic EPS (Detail) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended								12 Months Ended
	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2014
Earnings Per Share [Abstract]
Net earnings	$ 170.1	$ 63.7	$ 40.2	$ 33.5	$ 165.9	$ 54.0	$ 34.7	$ 32.5	$ 307.5	$ 287.1	$ 263.0
Basic Weighted-average shares outstanding									118.3	119.9	119.6
Basic EPS (in usd per share)	$ 1.44	$ 0.54	$ 0.34	$ 0.28	$ 1.39	$ 0.45	$ 0.29	$ 0.27	$ 2.60	$ 2.39	$ 2.20