XML 52 R41.htm IDEA: XBRL DOCUMENT
v3.20.2

Environmental Obligations - Additional Information (Detail) - USD ($) | 1 Months Ended | 3 Months Ended | 6 Months Ended |
--- | --- | --- | --- | ---
Jul. 31, 2012 | Jun. 30, 2020 | Jun. 30, 2019 | Jun. 30, 2020 | Jun. 30, 2019 | Dec. 31, 2019
Other Commitments [Line Items] |  |  |  |  |  |
Remediation agreement of lease |  |  |  | we have agreed to be responsible for environmental contamination at the premises that was known at the time the lease commenced, and for environmental contamination which existed prior to commencement of the lease and 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). |  |
The maximum number of years during lease term during which contamination is discovered that the Company may be responsible for |  |  |  | 10 years |  |
Estimated maximum remaining useful life of underground storage tanks that the company may be responsible for sold properties |  |  |  | 5 years |  |
Environmental remediation obligations |  | $ 49,273,000 |  | $ 49,273,000 |  | $ 50,723,000
Accretion expense |  |  |  | 922,000 | $ 1,032,000 |
Amount of credits to environmental expenses |  |  |  | 1,228,000 | 559,000 |
Changes in environmental estimates |  |  |  | 73,000 | 175,000 |
Increase in carrying value of property |  |  |  | $ 1,441,000 | 2,334,000 |
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 |  |  |  | $ 1,995,000 | 2,078,000 |
Capitalized asset retirement costs |  | 39,611,000 |  | 39,611,000 |  | 39,684,000
Impairments |  | 507,000 | $ 701,000 | 1,538,000 | 1,472,000 |
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 |  |  |  | 1,446,000 | $ 1,429,000 |
Reasonably Estimable Environmental Remediation Obligation [Member] |  |  |  |  |  |
Other Commitments [Line Items] |  |  |  |  |  |
Environmental remediation obligations |  | 11,487,000 |  | 11,487,000 |  | 12,470,000
Future Environmental Liabilities for Preexisting Unknown Contamination [Member] |  |  |  |  |  |
Other Commitments [Line Items] |  |  |  |  |  |
Environmental remediation obligations |  | 37,786,000 |  | 37,786,000 |  | 38,253,000
Capitalized asset retirement costs |  | 16,924,000 |  | 16,924,000 |  | 17,534,000
Known Environmental Liabilities [Member] |  |  |  |  |  |
Other Commitments [Line Items] |  |  |  |  |  |
Capitalized asset retirement costs |  | $ 22,687,000 |  | $ 22,687,000 |  | $ 22,150,000
Maximum [Member] |  |  |  |  |  |
Other Commitments [Line Items] |  |  |  |  |  |
The maximum number of years during lease term during which contamination is discovered that the Company may be responsible for |  |  |  | 10 years |  |
Environmental remediation liabilities discount rate |  | 7.00% |  | 7.00% |  |
Environmental remediation liability inflation rate adjustment |  |  |  | 2.75% |  |
Minimum [Member] |  |  |  |  |  |
Other Commitments [Line Items] |  |  |  |  |  |
Environmental remediation liabilities discount rate |  | 4.00% |  | 4.00% |  |
Environmental remediation liability inflation rate adjustment |  |  |  | 2.00% |  |

X
- Definition The inflation adjustment rate for environmental loss contingencies. + References No definition available. + Details
Name: | gty_AccrualForEnvironmentalLossContingenciesInflationAdjustmentRate
Namespace Prefix: | gty_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of credits to environmental expenses. + References No definition available. + Details
Name: | gty_AmountOfCreditsToEnvironmentalExpenses
Namespace Prefix: | gty_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Changes in environmental estimates. + References No definition available. + Details
Name: | gty_ChangesInEnvironmentalEstimates
Namespace Prefix: | gty_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The current period expense charged against earnings for the allocation of capitalized asset retirement costs over the remaining useful life of the underground storage tank or other period of time if circumstances warrant. + References No definition available. + Details
Name: | gty_DepreciationAndAmortizationForCapitalizedAssetRetirementCosts
Namespace Prefix: | gty_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition A general description of the nature of the existing leasing arrangements of a lessor. + References No definition available. + Details
Name: | gty_DescriptionOfLessorLeasingArrangements
Namespace Prefix: | gty_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The estimated maximum remaining useful life of underground storage tanks used to calculate depreciation of capitalized asset retirement costs. + References No definition available. + Details
Name: | gty_EstimatedMaximumRemainingUsefulLifeOfUndergroundStorageTankCapitalizedAssetRetirementCosts
Namespace Prefix: | gty_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition The estimated maximum remaining useful life of underground storage tanks that the company may be responsible for related to sold properties. + References No definition available. + Details
Name: | gty_EstimatedMaximumRemainingUsefulLifeOfUndergroundStorageTanksThatTheCompanyMayBeResponsibleForRelatedToSoldProperties
Namespace Prefix: | gty_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition The amount of the increase in the carrying value of the property. + References No definition available. + Details
Name: | gty_IncreaseInCarryingValueOfProperty
Namespace Prefix: | gty_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The number of years covered by the pollution legal liability insurance policy. + References No definition available. + Details
Name: | gty_PeriodCoveredByPollutionLegalLiabilityInsurancePolicy
Namespace Prefix: | gty_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition The maximum number of years during lease term during which contamination is discovered that the Company may be responsible for. + References No definition available. + Details
Name: | gty_PeriodDuringWhichContaminationDiscoveredThatCompanyIsResponsible
Namespace Prefix: | gty_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition The aggregate dollar limit of the pollution legal liability insurance policy. + References No definition available. + Details
Name: | gty_PollutionLegalLiabilityInsurancePolicyAggregateLimit
Namespace Prefix: | gty_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Total costs accrued as of the balance sheet date for environmental loss contingencies. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 450 -SubTopic 20 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=121557415&loc=d3e14326-108349 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 450 -SubTopic 20 -Section 25 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6395460&loc=d3e13647-108346 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 410 -SubTopic 30 -Section 50 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=6393242&loc=d3e13207-110859 + Details
Name: | us-gaap_AccrualForEnvironmentalLossContingencies
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Rate applied to the undiscounted amount of environmental loss contingencies to arrive at the present value recorded as of the balance sheet date. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 410 -SubTopic 30 -Section 50 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=6393242&loc=d3e13207-110859 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 450 -SubTopic 20 -Section S99 -Paragraph 1 -Subparagraph (SAB Topic 5.Y.Q1) -URI http://asc.fasb.org/extlink&oid=27011672&loc=d3e149879-122751 + Details
Name: | us-gaap_AccrualForEnvironmentalLossContingenciesDiscountRate
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3602-108585 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 45 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=109226348&loc=d3e2420-110228 + Details
Name: | us-gaap_AssetImpairmentCharges
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of accretion expense recognized during the period that is associated with an asset retirement obligation. Accretion expense measures and incorporates changes due to the passage of time into the carrying amount of the liability. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 410 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c)(3) -URI http://asc.fasb.org/extlink&oid=6392692&loc=d3e7535-110849 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 410 -SubTopic 20 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6392676&loc=d3e7480-110848 + Details
Name: | us-gaap_AssetRetirementObligationAccretionExpense
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The amount of asset retirement costs previously incurred and capitalized separately from the capitalized amount of the associated long-lived assets. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -SubTopic 235 -Section 50 -Paragraph 13 -URI http://asc.fasb.org/extlink&oid=68064819&loc=d3e61901-109447 + Details
Name: | us-gaap_CapitalizedCostsAssetRetirementCosts
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_OtherCommitmentsLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_StatementOperatingActivitiesSegmentAxis=gty_CapitalizedAssetRetirementCostsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_EnvironmentalRemediationContingencyAxis=gty_ReasonablyEstimableEnvironmentalRemediationObligationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_EnvironmentalRemediationContingencyAxis=gty_FutureEnvironmentalLiabilitiesForPreexistingUnknownContaminationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_EnvironmentalRemediationContingencyAxis=gty_KnownEnvironmentalLiabilitiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |