Consolidated Statements of Earnings and Comprehensive Income (Parenthetical) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Statement [Abstract]
Net gain (loss) from discontinued operations, tax expense (benefit)	$ 8.2	$ 3.6	$ (0.8)
(Loss) gain on disposal of discontinued business, tax (benefit)	$ (6.0)	$ (4.1)	$ (15.2)

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

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