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Employee benefit plans (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2018 CAD ($) $ / h	Dec. 31, 2017 CAD ($)
Retirement Benefits [Abstract]
Contributions made by the Company during the year | $	$ 991	$ 877
Company match of voluntary contributions made by employees, percentage of base salary	5.00%
Contribution per hour | $ / h	1.00

X

- Definition

Defined Contribution Plan, Employer Matching Contribution, Contribution Per Hour

+ References

No definition available.

+ Details

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Data Type:	us-types:perUnitItemType
Balance Type:	na
Period Type:	duration

X

- References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
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X

- Definition

Amount of cost for defined contribution plan.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 70
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=49170846&loc=d3e28014-114942

+ Details

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X

- Definition

Percentage of employees' gross pay for which the employer contributes a matching contribution to a defined contribution plan.

+ References

No definition available.

+ Details

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