Incentive Plans - Additional Information (Detail) - Incentive Plan 2007 - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Equity Incentive Plan [Line Items]
Number of shares authorized for issuance	175,000
Shares issued, net of cancellation	142,269
Number of shares vested	117,040
Number of shares remaining for issuance	32,731
Restricted shares issued, net of cancellation	15,064	10,165	10,765
Restricted shares issued, weighted average grant price	$ 52.30	$ 71.69	$ 96.74
Restricted shares of beneficial interest, net of cancellations, issued, value	$ 788,000	$ 729,000	$ 1,000,000.0
Restricted shares, Vesting Period		2023-06	2022-06
Compensation expense	780,000	$ 947,000	$ 912,000
Compensation expense remained to be recognized in future	$ 734,000
Compensation expense not yet recognized, period of recognition	1 year 2 months 12 days
Tranche One
Equity Incentive Plan [Line Items]
Restricted shares, Vesting Period	2024-06
Tranche Two
Equity Incentive Plan [Line Items]
Restricted shares, Vesting Period	2024-09
Tranche Three
Equity Incentive Plan [Line Items]
Restricted shares, Vesting Period	2024-11