CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE (LOSS) INCOME - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (19.9)	$ (37.6)
Other comprehensive (loss) income:
Currency translation adjustments	(39.1)	8.5
Amortization of cash flow hedge into income, net of tax expense ($0.1) for the three months ended March 31, 2019		0.2
Total other comprehensive (loss) income	(39.1)	8.7
Comprehensive loss	(59.0)	(28.9)
Less: comprehensive income attributable to noncontrolling interests	0.2	0.5
Comprehensive loss attributable to Stericycle, Inc. common shareholders	$ (59.2)	$ (29.4)