Net Income Per Share Information (Basic and Diluted Net Income Per Common Share) (Detail) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019
Numerator:
Net income attributable to Waste Connections for basic and diluted earnings per share	$ 143,035	$ 125,622
Denominator:
Basic shares outstanding	263,790,364	263,603,418
Dilutive effect of equity-based awards	562,794	733,512
Diluted shares outstanding	264,353,158	264,336,930

Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of share based payment arrangements using the treasury stock method.

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The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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Denominator used in the computation of basic and diluted net income per common.

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Numerator used in computation of basic and diluted net income per common share.

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