Condensed Consolidated Statements of Comprehensive Income (UNAUDITED) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Statement Of Income And Comprehensive Income [Abstract]
Net earnings	$ 35.2	$ 4.1
Other comprehensive income (loss), net of tax:
Translation adjustments	0.9	(2.8)
Adjustment for net periodic pension and other postretirement benefits plan	0.6	0.6
Other comprehensive income (loss), net of tax	1.5	(2.2)
Comprehensive income	$ 36.7	$ 1.9