Accounts Receivable, Net (Tables)

3 Months Ended

Mar. 31, 2021

Accounts Receivable, after Allowance for Credit Loss [Abstract]

Schedule of Accounts Receivable, Net

	As at March 31, 2021						As at March 31, 2020
(in millions of Canadian dollars)	Freight		Non-freight		Total		Freight		Non-freight		Total
Total accounts receivable	$	681	$	198	$	879	$	724	$	202	$	926
Allowance for credit losses	(24)		(15)		(39)		(27)		(14)		(41)
Total accounts receivable, net	$	657	$	183	$	840	$	697	$	188	$	885

Accounts Receivable, Allowance for Credit Loss

	For the three months ended March 31, 2021						For the three months ended March 31, 2020
(in millions of Canadian dollars)	Freight		Non-freight		Total		Freight		Non-freight		Total
Allowance for credit losses, opening balance	$	(25)	$	(15)	$	(40)	$	(27)	$	(16)	$	(43)
Current period credit loss provision, net	1		—		1		—		2		2
Allowance for credit losses, closing balance	$	(24)	$	(15)	$	(39)	$	(27)	$	(14)	$	(41)