Net Income Per Share Information (Basic and Diluted Net Income Per Common Share) (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Numerator:
Net income attributable to Waste Connections for basic and diluted earnings per share	$ (227,072)	$ 148,848	$ (84,037)	$ 274,470
Denominator:
Basic shares outstanding	262,994,275	263,846,970	263,390,685	263,725,867
Dilutive effect of equity-based awards		647,973		690,743
Diluted shares outstanding	262,994,275	264,494,943	263,390,685	264,416,610
Antidilutive shares excluded from computation of earnings per share	322,779		442,786