CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 26.2	$ (19.9)
Other comprehensive income (loss):
Currency translation adjustments	(13.1)	(39.1)
Total other comprehensive income (loss)	(13.1)	(39.1)
Comprehensive income (loss)	13.1	(59.0)
Less: comprehensive (loss) income attributable to noncontrolling interests	(0.1)	0.2
Comprehensive income (loss) attributable to Stericycle, Inc. common shareholders	$ 13.2	$ (59.2)