CONDENSED CONSOLIDATED STATEMENTS OF INCOME (LOSS) - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Income Statement [Abstract]
Revenues	$ 883.3		$ 1,778.3
Revenues		$ 917.7		$ 1,810.1
Cost of revenues	530.0	536.0	1,066.5	1,059.7
Gross profit	353.3	381.7	711.8	750.4
Selling, general and administrative expenses	290.9	574.0	595.3	828.2
Income (loss) from operations	62.4	(192.3)	116.5	(77.8)
Interest expense, net	(24.6)	(23.7)	(49.6)	(47.0)
Other expense, net	(0.6)	(1.7)	(0.6)	(3.2)
Income (loss) before income taxes	37.2	(217.7)	66.3	(128.0)
Income tax (expense) benefit	(9.6)	73.5	(16.2)	42.4
Net income (loss)	27.6	(144.2)	50.1	(85.6)
Net loss (income) attributable to noncontrolling interests	0.1	0.2	0.1	(0.2)
Net income (loss) attributable to Stericycle, Inc.	27.7	(144.0)	50.2	(85.8)
Mandatory convertible preferred stock dividend	(8.3)	(9.2)	(17.1)	(18.6)
Gain on repurchase of preferred stock	7.2	4.4	14.5	9.0
Net income (loss) attributable to Stericycle, Inc. common shareholders	$ 26.6	$ (148.8)	$ 47.6	$ (95.4)
Earnings (loss) per common share attributable to Stericycle, Inc. common shareholders:
Basic	$ 0.31	$ (1.74)	$ 0.56	$ (1.12)
Diluted	$ 0.31	$ (1.74)	$ 0.55	$ (1.12)
Weighted average number of common shares outstanding:
Basic	85.6	85.3	85.6	85.2
Diluted	85.8	85.3	85.8	85.2