Derivative Financial Instruments - Summary of Outstanding Interest Rate Derivatives Designated as Cash Flow Hedges of Interest Rate Risk (Detail) - Cash Flow Hedges [Member] - Designated as Hedging Instrument [Member] - Interest Rate Caps [Member] - CAD [Member] - CDOR [Member] $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2021 CAD ($) DerivativeInstrument	Dec. 31, 2020 CAD ($) DerivativeInstrument
Derivative [Line Items]
Number of Instruments | DerivativeInstrument	1	2
Notional Amount | $	$ 21,020	$ 38,293
Strike	1.00%	1.00%
Wtd. Avg. Maturity (Years)	2 months 12 days	9 months 18 days