Computation of Basic and Diluted Net Income Per Share (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Numerator:
Numerator for basic earnings per share Net income attributable to Stericycle, Inc.	$ 65,477	$ 59,247	$ 197,927	$ 170,463
Denominator:
Denominator for basic earnings per share weighted average shares	85,748,998	85,564,682	85,251,002	85,654,097
Effect of diluted securities:
Employee stock options	1,556,781	1,820,439	1,660,227	1,966,770
Denominator for diluted earnings per share-adjusted weighted averag e shares and after assumed conversions	87,305,779	87,385,121	86,911,229	87,620,867
Earnings per share - Basic	$ 0.76	$ 0.69	$ 2.32	$ 1.99
Earnings per share - Diluted	$ 0.75	$ 0.68	$ 2.28	$ 1.95