CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE (LOSS) INCOME - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Statement Of Income And Comprehensive Income [Abstract]
Net (loss) income	$ (37.6)	$ 22.5
Other comprehensive income:
Currency translation adjustments	8.5	16.3
Amortization of cash flow hedge into income, net of tax expense ($0.1 and $0.1) for the three months ended March 31, 2019 and 2018, respectively	0.2	0.1
Total other comprehensive income	8.7	16.4
Comprehensive (loss) income	(28.9)	38.9
Less: comprehensive income attributable to noncontrolling interests	0.5	0.1
Comprehensive (loss) income attributable to Stericycle, Inc. common shareholders	$ (29.4)	$ 38.8