Real Estate and Accumulated Depreciation - Changes in Total Real Estate Investments and Related Accumulated Depreciation (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Total real estate investments:
Balance, beginning of year	$ 2,284,126	$ 2,124,796	$ 2,081,597
Acquisitions	0	108,279	0
Improvements	130,300	54,177	45,396
Retirements	(6,290)	(3,126)	(2,197)
Balance, end of year	2,408,136	2,284,126	2,124,796
Total accumulated depreciation:
Balance, beginning of year	650,113	607,706	563,474
Depreciation expense	44,636	45,487	45,865
Retirements	(6,274)	(3,080)	(1,633)
Balance, end of year	$ 688,475	$ 650,113	$ 607,706