Quarterly Consolidated Financial Information (Unaudited) (Quarterly Financial Information Disclosure) - USD ($) $ in Millions	3 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Revenues	$ 265.3	$ 228.5	$ 257.7	$ 212.6	$ 266.9	$ 274.3	$ 234.0	$ 192.8
Gross profit	93.9	75.7	86.0	72.6	88.8	97.2	74.8	60.1
Operating income	40.7	20.0	35.8	20.3	39.0	47.2	22.2	15.9
Net Income (Loss) Attributable to Parent	$ 26.7	$ 11.2	$ 23.8	$ 10.3	$ 40.2	$ 33.7	$ 10.9	$ (21.0)
Net income (loss) per share(1)
Net income (loss) per basic share	$ 0.17	$ 0.07	$ 0.15	$ 0.07	$ 0.26	$ 0.21	$ 0.07	$ (0.13)
Net income (loss) per diluted share	$ 0.17	$ 0.07	$ 0.15	$ 0.06	$ 0.25	$ 0.21	$ 0.07	$ (0.13)