Unsecured Credit Agreements - Summary of Unsecured Credit Agreements (Parenthetical) (Detail) $ in Thousands, $ in Millions		6 Months Ended	12 Months Ended
		Jun. 30, 2022 USD ($)	Dec. 31, 2021 USD ($)	Jun. 30, 2022 CAD ($)
Debt Instrument [Line Items]
Long-term Debt		$ 1,856,377
Unsecured Debt
Debt Instrument [Line Items]
Long-term Debt		$ 1,751,933	$ 1,592,472
Unsecured Debt | 1 Month LIBOR
Debt Instrument [Line Items]
Interest rate		1.79%	0.10%	1.79%
Unsecured Debt | 1 Month LIBOR | 2022 Unsecured Term Loan
Debt Instrument [Line Items]
Basis spread on variable rate	[1]	1.00%
Unsecured Debt | 1 Month LIBOR | 2024 Unsecured Term Loan
Debt Instrument [Line Items]
Basis spread on variable rate	[1]	1.00%
Unsecured Debt | 1 Month LIBOR | 2026 Unsecured Term Loan
Debt Instrument [Line Items]
Basis spread on variable rate	[1]	1.00%
Unsecured Debt | 1 Month LIBOR | Revolving Credit Facilities
Debt Instrument [Line Items]
Basis spread on variable rate			1.00%
Unsecured Debt | 1 Month Canadian Dollar
Debt Instrument [Line Items]
Long-term Debt		$ 77,700		$ 100
Interest rate		2.23%		2.23%
Unsecured Debt | 1 Month Secured Overnight
Debt Instrument [Line Items]
Long-term Debt		$ 243,000
Interest rate		1.69%		1.69%

[1] At June 30, 2022 and December 31, 2021, one-month LIBOR was 1.79% and 0.10%, respectively.