Supplemental information - Changes in Non-cash Working Capital (Details) - CAD ($) $ in Thousands	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018
Supplemental information .
Accounts receivable	$ 48,913	$ (94,562)
Crude oil inventory	(1,638)	(10,646)
Prepaid expenses	(2,882)	(4,896)
Accounts payable and accrued liabilities	(137,209)	230,567
Income taxes payable	(31,994)	(1,651)
Working capital assumed in acquisitions		(58,841)
Initial recognition of IFRS 16 liability		(10,483)
Foreign exchange	2,590	(873)
Changes in non-cash working capital	(122,220)	48,615
Changes in non-cash operating working capital	(65,148)	(6,876)
Changes in non-cash investing working capital	(57,072)	55,491
Changes in non-cash working capital	$ (122,220)	$ 48,615

Adjustments for decrease (increase) in inventories to reconcile profit (loss) to net cash flow from (used in) operating activities. [Refer: Inventories; Profit (loss)]

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 7
-IssueDate 2019-01-01
-Paragraph 20
-Subparagraph a
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=7&code=ifrs-tx-2019-en-r&anchor=para_20_a&doctype=Standard
-URIDate 2019-03-27

+ Details

Name:	ifrs-full_AdjustmentsForDecreaseIncreaseInInventories
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Adjustments for decrease (increase) in other current assets to reconcile profit (loss) to net cash flow from (used in) operating activities. [Refer: Other current assets; Profit (loss)]

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 7
-IssueDate 2019-01-01
-Paragraph 20
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=7&code=ifrs-tx-2019-en-r&anchor=para_20&doctype=Standard
-URIDate 2019-03-27

+ Details

Name:	ifrs-full_AdjustmentsForDecreaseIncreaseInOtherCurrentAssets
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Adjustments for decrease (increase) in trade and other receivables to reconcile profit (loss) to net cash flow from (used in) operating activities. [Refer: Trade and other receivables; Profit (loss)]

+ References

+ Details

Name:	ifrs-full_AdjustmentsForDecreaseIncreaseInTradeAndOtherReceivables
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Adjustments for income tax expense to reconcile profit (loss) to net cash flow from (used in) operating activities. [Refer: Profit (loss)]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 7
-IssueDate 2019-01-01
-Paragraph 35
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=7&code=ifrs-tx-2019-en-r&anchor=para_35&doctype=Standard
-URIDate 2019-03-27

+ Details

Name:	ifrs-full_AdjustmentsForIncomeTaxExpense
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Adjustments for increase (decrease) in trade and other payables to reconcile profit (loss) to net cash flow from (used in) operating activities. [Refer: Trade and other payables; Profit (loss)]

+ References

+ Details

Name:	ifrs-full_AdjustmentsForIncreaseDecreaseInTradeAndOtherPayables
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The cash inflow (outflow) from the entity's operations before changes in working capital.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Name IAS
-Number 7
-IssueDate 2019-01-01
-Section A Statement of cash flows for an entity other than a financial institution
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=7&code=ifrs-tx-2019-en-r&doctype=Illustrative%20Examples&dita_xref=IAS07_IE_A_TI
-URIDate 2019-03-27

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 7
-IssueDate 2019-01-01
-Paragraph 20
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=7&code=ifrs-tx-2019-en-r&anchor=para_20&doctype=Standard
-URIDate 2019-03-27

+ Details

Name:	ifrs-full_CashFlowsFromUsedInOperationsBeforeChangesInWorkingCapital
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	duration

- Definition

Adjustments for non-cash items to reconcile profit (loss) to net cash flow from (used in) operating activities that the entity does not separately disclose in the same statement or note. [Refer: Profit (loss)]

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 7
-IssueDate 2019-01-01
-Paragraph 20
-Subparagraph b
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=7&code=ifrs-tx-2019-en-r&anchor=para_20_b&doctype=Standard
-URIDate 2019-03-27

+ Details

Name:	ifrs-full_OtherAdjustmentsForNoncashItems
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Adjustments for foreign exchange losses (gains) to reconcile profit (loss) to net cash flow from (used in) operating activities. [Refer: Profit (loss)]

+ References

No definition available.

+ Details

Name:	vet_AdjustmentsForForeignExchangeLossesGains
Namespace Prefix:	vet_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Adjustments for increase (decrease) in working capital through the initial recognition of IFRS 16 liability.

+ References

No definition available.

+ Details

Name:	vet_AdjustmentsForIncreaseDecreaseInWorkingCapitalThroughInitialRecognitionOfIFRS16Liability
Namespace Prefix:	vet_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- References

No definition available.

+ Details

Name:	vet_IncreaseDecreaseInWorkingCapitalAbstract
Namespace Prefix:	vet_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Increase (decrease) in working capital

+ References

No definition available.

+ Details

Name:	vet_IncreaseDecreaseInWorkingCapitals
Namespace Prefix:	vet_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Other adjustments for which cash effects are investing or financing cash flow

+ References

No definition available.

+ Details

Name:	vet_OtherAdjustmentsForWhichCashEffectsAreInvestingOrFinancingCashFlows
Namespace Prefix:	vet_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration