CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Statement [Abstract]
Revenues	$ 3,580.7	$ 3,562.3	$ 2,985.9
Cost of revenues	2,118.2	2,075.4	1,731.1
Gross profit	1,462.5	1,486.9	1,254.8
Selling, general and administrative expenses	1,470.1	1,053.1	767.2
(Loss) income from operations	(7.6)	433.8	487.6
Other income (expense):
Interest income	0.3	0.0	0.2
Interest expense	(94.0)	(97.8)	(77.5)
Other (expense) income, net	(6.6)	(7.9)	0.6
(Loss) income before income taxes	(107.9)	328.1	410.9
Income tax (benefit) expense	(150.9)	120.2	142.9
Net income	43.0	207.9	268.0
Net income attributable to noncontrolling interests	0.6	1.6	1.0
Net income attributable to Stericycle, Inc.	42.4	206.3	267.0
Mandatory convertible preferred stock dividend	36.3	39.4	10.1
Gain on repurchase of preferred stock	(17.3)	(11.3)	0.0
Net income attributable to Stericycle, Inc. common shareholders	$ 23.4	$ 178.2	$ 256.9
Earnings per common share attributable to Stericycle, Inc. common shareholders:
Basic	$ 0.27	$ 2.10	$ 3.02
Diluted	$ 0.27	$ 2.08	$ 2.98
Weighted average number of common shares Outstanding:
Basic	85.3	84.9	84.9
Diluted	85.6	85.6	86.2