Basic and Diluted Net Income Per Common Share (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Numerator:
Net income attributable to Waste Connections for basic and diluted earnings per share	$ 60,706	$ 49,385	$ 146,229	$ 123,104
Denominator:
Basic shares outstanding	123,676,936	123,031,259	123,557,317	120,571,106
Dilutive effect of stock options and warrants	182,175	303,293	192,054	319,457
Dilutive effect of restricted stock units	420,555	331,037	340,051	308,338
Diluted shares outstanding	124,279,666	123,665,589	124,089,422	121,198,901