Long-Term Debt - TH Facility (Details) - TH Facility	6 Months Ended
	Jun. 30, 2020 CAD ($)
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 225,000,000
Remaining borrowing capacity	125,000,000
Amount drawn	$ 225,000,000
Weighted average interest rate	1.93%
Canadian Bankers' Acceptance Rate
Line of Credit Facility [Line Items]
Basis spread on variable rate	1.40%
Prime Rate
Line of Credit Facility [Line Items]
Basis spread on variable rate	0.40%