Leases - Maturity analysis (Details) - CAD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Payments Finance Leases
2021	$ 28,969
2022	22,735
2023	13,942
2024	6,442
2025 and thereafter	1,358
Total minimum lease payments	73,446
Less: amount representing interest	(3,974)
Carrying amount of minimum lease payments	69,472
Less: current portion of leases	(26,895)	$ (29,206)
Finance lease obligations	42,577	47,072
Payments Operating Leases
2021	4,768
2022	3,702
2023	2,413
2024	1,193
2025 and thereafter	10,160
Total minimum lease payments	22,236
Less: amount representing interest	(4,114)
Carrying amount of minimum lease payments	18,122
Less: current portion of capital leases	(4,004)	(3,799)
Operating lease liabilities	14,118	$ 17,710
Receipts Operating Leases
2021	8,179
2022	7,276
2023	6,121
2024	493
2025 and thereafter	0
Total minimum lease payments	$ 22,069

Finance Lease, Liability, To Be Paid, After Year Four

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Lessee, Operating Lease, Liability, To Be Paid, After Year Four

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Lessor, Operating Lease, Payment To Be Received, After Year Four

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Receipts Operating Leases [Abstract]

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- Definition

Present value of lessee's discounted obligation for lease payments from finance lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 50
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=121609121&loc=SL77918701-209980

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-Publisher FASB
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-SubTopic 20
-Section 45
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121603541&loc=SL77918627-209977

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Present value of lessee's discounted obligation for lease payments from finance lease, classified as current.

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-Section 45
-Paragraph 1
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Present value of lessee's discounted obligation for lease payments from finance lease, classified as noncurrent.

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Amount of lessee's undiscounted obligation for lease payments for finance lease.

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Amount of lessee's undiscounted obligation for lease payment for finance lease to be paid in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of lessee's undiscounted obligation for lease payment for finance lease to be paid in fourth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of lessee's undiscounted obligation for lease payment for finance lease to be paid in third fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of lessee's undiscounted obligation for lease payment for finance lease to be paid in second fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of lessee's undiscounted obligation for lease payments in excess of discounted obligation for lease payments for finance lease.

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Amount of lessee's undiscounted obligation for lease payment for operating lease.

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Amount of lessee's undiscounted obligation for lease payment for operating lease to be paid in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of lessee's undiscounted obligation for lease payment for operating lease to be paid in fourth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of lessee's undiscounted obligation for lease payment for operating lease to be paid in third fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of lessee's undiscounted obligation for lease payment for operating lease to be paid in second fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of lessee's undiscounted obligation for lease payments in excess of discounted obligation for lease payments for operating lease.

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Amount of lease payments to be received by lessor for operating lease.

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-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 30
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Amount of lease payment to be received by lessor for operating lease in fourth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of lease payment to be received by lessor for operating lease in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of lease payment to be received by lessor for operating lease in third fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Present value of lessee's discounted obligation for lease payments from operating lease.

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Present value of lessee's discounted obligation for lease payments from operating lease, classified as current.

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Present value of lessee's discounted obligation for lease payments from operating lease, classified as noncurrent.

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