Line of Credit Facility, Extension Option, Period

No definition available.

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Namespace Prefix:	ivtp_
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Period Type:	duration

- Definition

Recourse Debt

+ References

No definition available.

+ Details

Name:	ivtp_RecourseDebt
Namespace Prefix:	ivtp_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- 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

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Period Type:	duration

- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(16))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

Name:	us-gaap_LineOfCredit
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The fee, expressed as a percentage of the line of credit facility, for the line of credit facility regardless of whether the facility has been used.

+ References

No definition available.

+ Details

Name:	us-gaap_LineOfCreditFacilityCommitmentFeePercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

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- Details

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- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_RevolvingCreditFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ivtp_CreditFacilityTrancheAxis=ivtp_A5YearTrancheMember
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Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=us-gaap_LondonInterbankOfferedRateLIBORMember
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Data Type:	na
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- Details

Name:	ivtp_CreditFacilityTrancheAxis=ivtp_A7YearTrancheMember
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- Details

Name:	us-gaap_LineOfCreditFacilityAxis=ivtp_KeyBancCapitalMarketsandJ.P.MorganSecuritiesLLCAmendedandRestatedMember
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Debt - Narrative (Details) - USD ($)	6 Months Ended	12 Months Ended
Debt - Narrative (Details) - USD ($)	Jun. 30, 2018	Dec. 31, 2017	Nov. 05, 2015	Nov. 04, 2015	Feb. 03, 2015	Feb. 02, 2015
Wells Fargo, Merrill Lynch, Pierce Fenner & Smith, PNC Capital Markets Credit Facility
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity			$ 600,000,000	$ 300,000,000
The Company
Debt Instrument [Line Items]
Recourse debt	$ 3,000,000
Revolving Credit Facility \| Wells Fargo, Merrill Lynch, Pierce Fenner & Smith, PNC Capital Markets Credit Facility
Debt Instrument [Line Items]
Long-term line of credit	300,000,000	$ 300,000,000
Revolving Credit Facility \| Wells Fargo, Merrill Lynch, Pierce Fenner & Smith, PNC Capital Markets Credit Facility \| 5-Year Tranche
Debt Instrument [Line Items]
Long-term line of credit	$ 50,000,000	$ 50,000,000
Revolving Credit Facility \| Wells Fargo, Merrill Lynch, Pierce Fenner & Smith, PNC Capital Markets Credit Facility \| 5-Year Tranche \| One-month LIBOR
Debt Instrument [Line Items]
Basis spread on variable interest rate (percent)	1.30%	1.30%
Revolving Credit Facility \| Wells Fargo, Merrill Lynch, Pierce Fenner & Smith, PNC Capital Markets Credit Facility \| 7-Year Tranche
Debt Instrument [Line Items]
Long-term line of credit	$ 100,000,000	$ 100,000,000
Revolving Credit Facility \| Wells Fargo, Merrill Lynch, Pierce Fenner & Smith, PNC Capital Markets Credit Facility \| 7-Year Tranche \| One-month LIBOR
Debt Instrument [Line Items]
Basis spread on variable interest rate (percent)	1.60%	1.60%
Revolving Credit Facility \| KeyBanc Capital Markets and J.P. Morgan Securities LLC Amended and Restated
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity					$ 600,000,000	$ 300,000,000
Extension option on line of credit, period	1 year
Commitment fee	0.15%
Line of credit facility, remaining borrowing capacity	$ 300,000,000