CONDENSED CONSOLIDATED STATEMENTS OF (LOSS) INCOME (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Income Statement [Abstract]
Revenues	$ 664.2	$ 668.0
Cost of revenues	419.7	406.6
Gross profit	244.5	261.4
Selling, general and administrative expenses	238.6	202.3
Income from operations	5.9	59.1
Interest expense, net	(16.3)	(18.4)
Other expense, net	(0.8)	(0.7)
(Loss) income before income taxes	(11.2)	40.0
Income tax expense	(2.9)	(13.8)
Net (loss) income	(14.1)	26.2
Net income attributable to noncontrolling interests	(0.1)	(0.1)
Net (loss) income attributable to Stericycle, Inc. common shareholders	$ (14.2)	$ 26.1
(Loss) earnings per common share attributable to Stericycle, Inc. common shareholders:
Basic (in dollars per share)	$ (0.15)	$ 0.29
Diluted (in dollars per share)	$ (0.15)	$ 0.28
Weighted average number of common shares outstanding:
Basic (in shares)	92.0	91.6
Diluted (in shares)	92.0	92.0