Marketable securities (Details) - CAD ($) $ in Thousands	12 Months Ended
May 31, 2019	May 31, 2018
Marketable securities
Marketable securities classified as Fair value through profit or loss	$ 20,199	$ 45,062
Gain/loss on marketable securities portfolio	(178)	(2,155)
Marketable securities
Marketable securities
Marketable securities classified as Fair value through profit or loss	20,199	45,062
Marketable securities, cost	20,907	45,863
Proceeds from disposal of marketable securities	24,685	47,495
Gain/loss on disposal	18	(608)
Marketable securities, reinvested	0	7,365
Gain/loss on marketable securities portfolio	(178)	(2,155)
Unrealized Fair value adjustments	$ (196)	$ (1,547)
Ford Motor Credit Co. LLC
Marketable securities
Interest rate (as a percent)	3.70%	3.70%
Marketable securities classified as Fair value through profit or loss		$ 1,015
Sobeys Inc.
Marketable securities
Interest rate (as a percent)	3.52%	3.52%
Marketable securities classified as Fair value through profit or loss		$ 3,040
Canadian Western Bank
Marketable securities
Interest rate (as a percent)	3.077%	3.077%
Marketable securities classified as Fair value through profit or loss		$ 1,528
Sun Life Financial Inc.
Marketable securities
Interest rate (as a percent)	2.77%	2.77%
Marketable securities classified as Fair value through profit or loss		$ 3,018
Ford Motor Credit Co. LLC
Marketable securities
Interest rate (as a percent)	3.14%	3.14%
Marketable securities classified as Fair value through profit or loss	$ 5,074	$ 5,101
Canadian Western Bank
Marketable securities
Interest rate (as a percent)	3.463%	3.463%
Marketable securities classified as Fair value through profit or loss	$ 1,019	$ 1,025
Laurentian Bank of Canada
Marketable securities
Interest rate (as a percent)	2.50%	2.50%
Marketable securities classified as Fair value through profit or loss		$ 3,003
Enercare Solutions Inc.
Marketable securities
Interest rate (as a percent)	4.60%	4.60%
Marketable securities classified as Fair value through profit or loss	$ 3,907	$ 3,974
Enbridge Inc.
Marketable securities
Interest rate (as a percent)	4.53%	4.53%
Marketable securities classified as Fair value through profit or loss	$ 5,137	$ 5,203
Choice Properties REIT
Marketable securities
Interest rate (as a percent)	3.60%	3.60%
Marketable securities classified as Fair value through profit or loss	$ 5,062	$ 5,091
Westcoast Energy Inc.
Marketable securities
Interest rate (as a percent)	4.57%	4.57%
Marketable securities classified as Fair value through profit or loss		$ 5,293
Citigroup Inc.
Marketable securities
Interest rate (as a percent)	2.05%	2.05%
Marketable securities classified as Fair value through profit or loss		$ 3,914
Royal Bank of Canada
Marketable securities
Interest rate (as a percent)	1.625%	1.625%
Marketable securities classified as Fair value through profit or loss		$ 3,857

Amount of reinvestment in Marketable securities.

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The gain (loss) recognized on the measurement to fair value less costs from marketable securities

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Amount of investment in marketable securities, classified as current.

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The increase (decrease) in the fair value of a financial asset (or group of financial assets) designated as measured at fair value through profit or loss that is attributable to unrealized adjustments.

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Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes of the table.

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The effective interest rate of financial assets reclassified out of the fair value through profit or loss measurement category. [Refer: Financial assets at fair value through profit or loss]

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The amount of financial assets at amortised cost. The amortised cost is the amount at which financial assets are measured at initial recognition minus principal repayments, plus or minus the cumulative amortisation using the effective interest method of any difference between that initial amount and the maturity amount, and adjusted for any impairment. [Refer: Financial assets]

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The gain (loss) recognised on the measurement to fair value less costs to sell or on the disposal of the assets or disposal group(s) constituting the discontinued operation. [Refer: Discontinued operations [member]]

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The cash inflow from sales or maturity of financial instruments, classified as investing activities. [Refer: Financial instruments, class [member]]

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