CONDENSED CONSOLIDATED STATEMENTS OF INCOME (LOSS) - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Income Statement [Abstract]
Revenues	$ 854.9	$ 882.8	$ 2,633.2	$ 2,692.9
Cost of revenues	519.4	514.7	1,585.9	1,574.4
Gross profit	335.5	368.1	1,047.3	1,118.5
Selling, general and administrative expenses	267.2	274.5	862.5	1,102.7
Income from operations	68.3	93.6	184.8	15.8
Interest expense, net	(27.7)	(24.5)	(77.3)	(71.5)
Other expense, net	(6.2)	(2.3)	(6.8)	(5.5)
Income (loss) before income taxes	34.4	66.8	100.7	(61.2)
Income tax (expense) benefit	(10.9)	(27.8)	(27.1)	14.6
Net income (loss)	23.5	39.0	73.6	(46.6)
Net loss (income) attributable to noncontrolling interests			0.1	(0.2)
Net income (loss) attributable to Stericycle, Inc.	23.5	39.0	73.7	(46.8)
Mandatory convertible preferred stock dividend	(8.4)	(8.9)	(25.5)	(27.5)
Gain on repurchases of preferred stock	2.4	5.4	16.9	14.4
Net income (loss) attributable to Stericycle, Inc. common shareholders	$ 17.5	$ 35.5	$ 65.1	$ (59.9)
Earnings (loss) per common share attributable to Stericycle, Inc. common shareholders:
Basic	$ 0.20	$ 0.42	$ 0.76	$ (0.70)
Diluted	$ 0.20	$ 0.41	$ 0.76	$ (0.70)
Weighted average number of common shares outstanding:
Basic	86.7	85.3	85.9	85.3
Diluted	86.8	85.6	86.1	85.3