CONDENSED CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Income Statement [Abstract]
Revenues	$ 895.0	$ 892.4
Cost of revenues	536.5	523.7
Gross profit	358.5	368.7
Selling, general and administrative expenses	304.4	254.2
Income from operations	54.1	114.5
Other income (expense):
Interest expense, net	(25.0)	(23.3)
Other expense, net		(1.5)
Income before income taxes	29.1	89.7
Income tax expense	(6.6)	(31.1)
Net income	22.5	58.6
Net income attributable to noncontrolling interests		(0.4)
Net income attributable to Stericycle, Inc.	22.5	58.2
Mandatory convertible preferred stock dividend	(8.8)	(9.4)
Gain on repurchase of preferred stock	7.3	4.6
Net income attributable to Stericycle, Inc. common shareholders	$ 21.0	$ 53.4
Earnings per common share attributable to Stericycle, Inc. common shareholders:
Basic	$ 0.25	$ 0.63
Diluted	$ 0.25	$ 0.62
Weighted average number of common shares outstanding:
Basic	85.5	85.2
Diluted	85.8	85.6