Line of Credit Facility, Extension Option, Period

No definition available.

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- Definition

[Line Items] for Mortgages Payable [Table]

+ References

No definition available.

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- Definition

Number Of Interest Rate Swaps

+ References

No definition available.

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- Definition

Number of Lenders

+ References

No definition available.

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- Definition

Number of tranches in loan credit facility

+ References

No definition available.

+ Details

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- Definition

Recourse Debt

+ References

No definition available.

+ Details

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Balance Type:	credit
Period Type:	instant

- Definition

Amount of outstanding long-term debt or borrowing associated with any securities or credit agreement for which there has been a default in principal, interest, sinking fund, or redemption provisions, or any breach of covenant that existed at the end of the period and subsequently has not been cured.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(c))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

+ Details

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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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- Definition

Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

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- 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

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-Name Accounting Standards Codification
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-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

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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

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Balance Type:	na
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- 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

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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

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Namespace Prefix:	us-gaap_
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Balance Type:	credit
Period Type:	instant

- Definition

The fair value of loans assumed in noncash investing or financing activities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4332-108586

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-Publisher FASB
-Name Accounting Standards Codification
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-Section 50
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-Name Accounting Standards Codification
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-SubTopic 10
-Section 50
-Paragraph 4
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+ Details

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Balance Type:	credit
Period Type:	duration

- Definition

Indicates the number of mortgages under each classification.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 948
-SubTopic 310
-Section S99
-Paragraph 1
-Subparagraph (SX 210.12-29.3)
-URI http://asc.fasb.org/extlink&oid=6589523&loc=d3e617274-123014

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 10
-Section S99
-Paragraph 6
-Subparagraph (SX 210.5-04.(c) Schedule IV)
-URI http://asc.fasb.org/extlink&oid=27047687&loc=d3e5864-122674

+ Details

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- Definition

The number of businesses acquired by the entity during the period.

+ References

No definition available.

+ Details

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- Details

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Debt - Narrative (Details)	9 Months Ended	12 Months Ended
Debt - Narrative (Details)	Sep. 30, 2017	Dec. 31, 2017 USD ($) acquisition swap Loans	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Nov. 05, 2015 USD ($) lender tranche	Nov. 04, 2015 USD ($)	Feb. 03, 2015 USD ($)
Mortgages Payable [Line Items]
Number of loans in default \| Loans		2
Loans assumed		$ 41,717,000	$ 16,000,000	$ 0
Number of businesses acquired \| acquisition		1
Long-term line of credit			300,000,000
Number of interest rate swaps \| swap		2
Mortgages [Member]
Mortgages Payable [Line Items]
Debt default, amount			3,151,000
The Company [Member]
Mortgages Payable [Line Items]
Recourse debt		$ 3,000,000
IAGM Retail Fund I, LLC [Member]
Mortgages Payable [Line Items]
Recourse debt		23,000,000
Wells Fargo, Merrill Lynch, Pierce Fenner Smith, PNC Capital Markets Credit Facility [Member]
Mortgages Payable [Line Items]
Maximum borrowing capacity					$ 600,000,000	$ 300,000,000
Number of lenders \| lender					7
Number of tranches in loan credit facility \| tranche					2
Wells Fargo, Merrill Lynch, Pierce Fenner Smith, PNC Capital Markets Credit Facility [Member] \| Revolving Credit Facility [Member]
Mortgages Payable [Line Items]
Long-term line of credit		$ 300,000,000	300,000,000
KeyBanc Capital Markets and J.P. Morgan Securities LLC Amended and Restated [Member] \| Revolving Credit Facility [Member]
Mortgages Payable [Line Items]
Maximum borrowing capacity					$ 300,000,000		$ 600,000,000
Basis spread on variable rate		1.40%
Extension option, period		1 year
Commitment fee percentage		0.15%
Remaining borrowing capacity		$ 300,000,000
5-Year Tranche [Member] \| Wells Fargo, Merrill Lynch, Pierce Fenner Smith, PNC Capital Markets Credit Facility [Member]
Mortgages Payable [Line Items]
Debt Instrument, Term		5 years
5-Year Tranche [Member] \| Wells Fargo, Merrill Lynch, Pierce Fenner Smith, PNC Capital Markets Credit Facility [Member] \| Revolving Credit Facility [Member]
Mortgages Payable [Line Items]
Long-term line of credit		$ 50,000,000	$ 50,000,000
5-Year Tranche [Member] \| London Interbank Offered Rate (LIBOR) [Member] \| Wells Fargo, Merrill Lynch, Pierce Fenner Smith, PNC Capital Markets Credit Facility [Member]
Mortgages Payable [Line Items]
Basis spread on variable rate	1.30%
5-Year Tranche [Member] \| London Interbank Offered Rate (LIBOR) [Member] \| Wells Fargo, Merrill Lynch, Pierce Fenner Smith, PNC Capital Markets Credit Facility [Member] \| Revolving Credit Facility [Member]
Mortgages Payable [Line Items]
Basis spread on variable rate		1.30%	1.30%
7-Year Tranche [Member] \| Wells Fargo, Merrill Lynch, Pierce Fenner Smith, PNC Capital Markets Credit Facility [Member]
Mortgages Payable [Line Items]
Debt Instrument, Term		7 years
7-Year Tranche [Member] \| Wells Fargo, Merrill Lynch, Pierce Fenner Smith, PNC Capital Markets Credit Facility [Member] \| Revolving Credit Facility [Member]
Mortgages Payable [Line Items]
Long-term line of credit		$ 100,000,000	$ 100,000,000
7-Year Tranche [Member] \| London Interbank Offered Rate (LIBOR) [Member] \| Wells Fargo, Merrill Lynch, Pierce Fenner Smith, PNC Capital Markets Credit Facility [Member]
Mortgages Payable [Line Items]
Basis spread on variable rate	1.60%
7-Year Tranche [Member] \| London Interbank Offered Rate (LIBOR) [Member] \| Wells Fargo, Merrill Lynch, Pierce Fenner Smith, PNC Capital Markets Credit Facility [Member] \| Revolving Credit Facility [Member]
Mortgages Payable [Line Items]
Basis spread on variable rate		1.60%	1.60%
Interest Rate Swap [Member] \| 5-Year Tranche [Member] \| Wells Fargo, Merrill Lynch, Pierce Fenner Smith, PNC Capital Markets Credit Facility [Member]
Mortgages Payable [Line Items]
Long-term line of credit		$ 150,000,000
Stonecrest Marketplace [Member] \| Mortgages [Member]
Mortgages Payable [Line Items]
Debt default, amount		37,866,000
Bellerive Plaza [Member] \| Mortgages [Member]
Mortgages Payable [Line Items]
Debt default, amount		$ 6,464,000