Quarterly Results of Operations (Unaudited) - Narrative (Details) - USD ($) $ / shares in Units, $ in Millions		12 Months Ended
	Mar. 21, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Restructuring Cost and Reserve [Line Items]
Severance, restructuring and impairment expenses	$ 6.7	$ 7.7	$ 0.0	$ 6.7
Restructuring and Impairment Charges
Restructuring Cost and Reserve [Line Items]
Reduction in after-tax earnings		$ 6.3
Reduction in after-tax earnings per share (in dollars per share)		$ 0.04