CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 29.3	$ (4.1)	$ 55.5	$ (24.0)
Other comprehensive income (loss):
Currency translation adjustments	6.7	10.3	(6.4)	(28.8)
Total other comprehensive income (loss)	6.7	10.3	(6.4)	(28.8)
Comprehensive income (loss)	36.0	6.2	49.1	(52.8)
Less: comprehensive income attributable to noncontrolling interests	0.1	0.4	0.0	0.7
Comprehensive income (loss) attributable to Stericycle, Inc. common shareholders	$ 35.9	$ 5.8	$ 49.1	$ (53.5)