Condensed Consolidated Statements of Earnings and Comprehensive Income (Parenthetical) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Income Statement [Abstract]
Net earnings (loss) from discontinued operations, tax expense	$ 0.2	$ 3.7	$ 1.7	$ 6.5
(Loss) from disposal of discontinued business, tax (benefit) expense	$ 0.1	$ 0.2	$ (0.3)	$ 0.5

Amount of tax expense (benefit) on gain (loss) not previously recognized resulting from the disposal of a discontinued operation.

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