XML 57 R41.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Derivative Financial Instruments - Additional Information (Detail) - USD ($) | 3 Months Ended | 9 Months Ended | 12 Months Ended |  |  |
--- | --- | --- | --- | --- | --- | ---
Sep. 30, 2017 | Sep. 30, 2017 | Sep. 30, 2018 | Apr. 17, 2017 | Dec. 31, 2016 | Jun. 24, 2016
Derivative Instruments Gain Loss [Line Items] |  |  |  |  |  |
Derivative, notional amount | $ 350,000,000 | $ 350,000,000 |  |  | $ 350,000,000 |
Derivative, strike rate for the interest rate swap contract |  |  |  | 1.1325% |  | 1.145%
Realized gains (losses) on interest rate hedges reclassified to earnings | 27,000 | (156,000) |  |  |  |
Interest Rate Swap |  |  |  |  |  |
Derivative Instruments Gain Loss [Line Items] |  |  |  |  |  |
Derivative, notional amount | 150,000,000 | $ 150,000,000 |  |  |  | $ 150,000
Derivative, maturity date |  | Jun. 17, 2021 |  |  |  |
Recognition of hedge ineffectiveness | (12,000) | $ 0 |  |  |  |
Interest Rate Swap | Cash Flow Hedge |  |  |  |  |  |
Derivative Instruments Gain Loss [Line Items] |  |  |  |  |  |
Derivative, notional amount | $ 150,000,000 | $ 150,000,000 |  |  | $ 150,000,000 |
Interest Rate Swaps and Caps | Scenario, Forecast | Cash Flow Hedge |  |  |  |  |  |
Derivative Instruments Gain Loss [Line Items] |  |  |  |  |  |
Reclassified out of accumulated other comprehensive income to earnings, amount |  |  | $ 471,000 |  |  |

X
- Definition Aggregate notional amount specified by the derivative(s). Expressed as an absolute value. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Article 12 -Section 13 -Sentence Column B + Details
Name: | invest_DerivativeNotionalAmount
Namespace Prefix: | invest_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | instant

X
- Definition Interest rate cash flow hedge gain loss reclassified to earnings net of mark to market. + References No definition available. + Details
Name: | irt_InterestRateCashFlowHedgeGainLossReclassifiedToEarningsNetOfMarkToMarket
Namespace Prefix: | irt_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

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_DerivativeInstrumentsGainLossLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The effective portion of net gain (loss) reclassified from accumulated other comprehensive income into income on derivative instruments designated and qualifying as hedging instruments. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4C -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5624171-113959 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4D -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5624177-113959 + Details
Name: | us-gaap_DerivativeInstrumentsGainLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortionNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Date the derivative contract matures, in CCYY-MM-DD format. + References No definition available. + Details
Name: | us-gaap_DerivativeMaturityDates
Namespace Prefix: | us-gaap_
Data Type: | xbrli:dateItemType
Balance Type: | na
Period Type: | duration

X
- Definition Fixed interest rate that will be received or paid upon exercise of the interest rate swaption contract. + References No definition available. + Details
Name: | us-gaap_DerivativeSwaptionInterestRate
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition The net gain (loss) during the reporting period due to ineffectiveness in interest rate cash flow hedges. Recognized in earnings. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4C -Subparagraph (d)(1) -URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5624171-113959 + Details
Name: | us-gaap_GainLossOnInterestRateCashFlowHedgeIneffectiveness
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=us-gaap_InterestRateSwapMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis=us-gaap_CashFlowHedgingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=irt_InterestRateSwapsAndCapsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementScenarioAxis=us-gaap_ScenarioForecastMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |