CONSOLIDATED STATEMENTS OF LOSS - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Statement [Abstract]
Revenues	$ 2,675.5	$ 3,308.9	$ 3,485.9
Cost of revenues	1,622.4	2,134.4	2,109.9
Gross profit	1,053.1	1,174.5	1,376.0
Selling, general and administrative expenses	897.6	1,055.1	1,165.6
Goodwill impairment	0.0	228.3	358.7
Divestiture losses (gains), net	123.6	103.0	12.8
Income (loss) from operations	31.9	(211.9)	(161.1)
Interest expense, net	(81.9)	(118.3)	(106.0)
Loss on early extinguishment of debt	0.0	(23.1)	0.0
Other expense, net	(6.0)	(9.5)	(8.3)
Loss before income taxes	(56.0)	(362.8)	(275.4)
Income tax benefit	0.1	16.8	29.8
Net loss	(55.9)	(346.0)	(245.6)
Net (income) loss attributable to noncontrolling interests	(1.4)	(0.8)	0.9
Net loss attributable to Stericycle, Inc.	(57.3)	(346.8)	(244.7)
Mandatory convertible preferred stock dividend	0.0	0.0	(25.5)
Gain on repurchase of preferred stock	0.0	0.0	16.9
Net loss attributable to Stericycle, Inc. common shareholders	$ (57.3)	$ (346.8)	$ (253.3)
Loss per common share attributable to Stericycle, Inc. common shareholders:
Basic (in dollars per share)	$ (0.63)	$ (3.81)	$ (2.91)
Diluted (in dollars per share)	$ (0.63)	$ (3.81)	$ (2.91)
Weighted average number of common shares Outstanding:
Basic (in shares)	91.5	91.0	87.1
Diluted (in shares)	91.5	91.0	87.1