Environmental Obligations - Additional Information (Detail) - USD ($)	1 Months Ended	3 Months Ended		6 Months Ended
	Jul. 31, 2012	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Other Commitments [Line Items]
Remediation agreement of lease				we agreed to be responsible for environmental contamination that was known at the time the lease commenced, and for unknown environmental contamination which existed prior to commencement of the lease and which is discovered (other than as a result of a voluntary site investigation) during the first 10 years of the lease term (or a shorter period for a minority of such leases) (a “Lookback Period”).
The maximum number of years during lease term during which contamination is discovered that the Company may be responsible for				10 years
Lookback Period				5 years
Unknown reserve liabilities removed		$ 16,790,000
Amount of credits to environmental expenses		16,333,000		$ 17,534,000	$ 1,039,000
Unknown reserve liabilities				7,400,000
Environmental remediation obligations		29,549,000		29,549,000		$ 47,597,000
Accretion expense				822,000	863,000
Changes in environmental estimates				1,749,000	92,000
Increase in carrying value of property				$ 1,194,000	1,211,000
Estimated maximum remaining useful life of underground storage tanks used to calculate depreciation of capitalized asset retirement costs				10 years
Depreciation and amortization expense for capitalized asset retirement costs				$ 1,946,000	1,971,000
Capitalized asset retirement costs		37,642,000		37,642,000		39,670,000
Impairments		$ 391,000	$ 756,000	1,429,000	1,532,000
Pollution legal liability insurance policy duration	10 years
Pollution legal liability insurance policy aggregate limit	$ 50,000,000
Capitalized Asset Retirement Costs [Member]
Other Commitments [Line Items]
Impairments				$ 735,000	$ 1,500,000
Minimum [Member]
Other Commitments [Line Items]
Environmental remediation liabilities discount rate		4.00%		4.00%
Environmental remediation liability inflation rate adjustment				2.00%
Maximum [Member]
Other Commitments [Line Items]
Environmental remediation liabilities discount rate		7.00%		7.00%
Environmental remediation liability inflation rate adjustment				2.75%
Reasonably Estimable Environmental Remediation Obligation [Member]
Other Commitments [Line Items]
Environmental remediation obligation known reserve liabilities		$ 10,643,000		$ 10,643,000		11,382,000
Future Environmental Liabilities for Preexisting Unknown Contamination [Member]
Other Commitments [Line Items]
Environmental remediation obligation unknown reserve liabilities		18,906,000		18,906,000		36,215,000
Capitalized asset retirement costs		12,903,000		12,903,000		15,595,000
Known Environmental Liabilities [Member]
Other Commitments [Line Items]
Capitalized asset retirement costs		$ 24,739,000		$ 24,739,000		$ 24,075,000