Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement of Comprehensive Income [Abstract]
Tax expense (benefit) on other comprehensive income (loss) from equity method investments	$ 0.0	$ 0.0	$ 2.2