CONDENSED CONSOLIDATED STATEMENTS OF LOSS - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Income Statement [Abstract]
Revenue	$ 636.4	$ 833.1	$ 2,019.6	$ 2,509.0
Cost of revenues	369.1	537.8	1,236.0	1,614.0
Gross profit	267.3	295.3	783.6	895.0
Selling, general and administrative expenses	219.0	246.6	678.7	809.4
Divestiture losses (gains), net	104.1	83.2	166.2	78.1
Goodwill impairment	0.0	0.0	0.0	20.9
Loss from operations	(55.8)	(34.5)	(61.3)	(13.4)
Interest expense, net	(17.7)	(29.9)	(62.0)	(91.1)
Loss on early extinguishment of debt	0.0	0.0	0.0	(23.1)
Other expense, net	(0.9)	(3.2)	(4.8)	(7.2)
Loss before income taxes	(74.4)	(67.6)	(128.1)	(134.8)
Income tax (expense) benefit	(6.5)	8.6	23.2	8.0
Net loss	(80.9)	(59.0)	(104.9)	(126.8)
Net income attributable to noncontrolling interests	(0.3)	(0.2)	(0.9)	(0.7)
Net loss attributable to Stericycle, Inc. common shareholders	$ (81.2)	$ (59.2)	$ (105.8)	$ (127.5)
Loss per common share attributable to Stericycle, Inc. common shareholders:
Basic (in dollars per share)	$ (0.89)	$ (0.65)	$ (1.16)	$ (1.40)
Diluted (in dollars per share)	$ (0.89)	$ (0.65)	$ (1.16)	$ (1.40)
Weighted average number of common shares outstanding:
Basic (in shares)	91.5	91.1	91.4	91.0
Diluted (in shares)	91.5	91.1	91.4	91.0