Debt instrument, default interest.

No definition available.

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- Definition

Decrease in future availability of mortgage loan.

+ References

No definition available.

+ Details

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- Definition

Income recognized from tax credit transactions.

+ References

No definition available.

+ Details

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- Definition

Increase (decrease) in mortgage loans.

+ References

No definition available.

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- Definition

Number of properties collateralized.

+ References

No definition available.

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- Definition

Outstanding mortgage loan amount.

+ References

No definition available.

+ Details

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- Definition

Percentage of tax credits on qualifying invested equity loans.

+ References

No definition available.

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- Definition

Prepayment of line of credit.

+ References

No definition available.

+ Details

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- Definition

Redemption of loan expiration period.

+ References

No definition available.

+ Details

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- Definition

Transfer of tax credit transactions to investors exchange amount.

+ References

No definition available.

+ Details

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Balance Type:	credit
Period Type:	duration

- Definition

Number of mortgage loans within investment in mortgage loan on real estate by entity with substantial portion of business acquiring and holding investment real estate or interest in real estate.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 12
-Footnote 3
-Subsection 29

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 948
-SubTopic 310
-Section S99
-Paragraph 1
-Subparagraph (SX 210.12-29(Footnote 3))
-URI http://asc.fasb.org/extlink&oid=6589523&loc=d3e617274-123014

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- 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://fasb.org/us-gaap/role/ref/legacyRef
-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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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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Balance Type:	na
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- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28551-108399

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-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400

+ Details

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Period Type:	instant

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

+ Details

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Period Type:	instant

- 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

Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(2))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (bbb)(2)
-URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258

+ Details

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- Definition

Amount of the required periodic payments applied to principal.

+ References

+ Details

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Period Type:	duration

- Definition

Average fixed interest rate related to the group of interest rate derivatives.

+ References

No definition available.

+ Details

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- Definition

Nominal or face amount used to calculate payment on derivative.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1B
-URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5580258-113959

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
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-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1A
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5579245-113959

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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://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
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-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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-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=119400593&loc=d3e572229-122910

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Balance Type:	credit
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- Definition

The value (monetary amount) of the award the plaintiff seeks in the legal matter.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
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-Section 50
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-Topic 450
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Balance Type:	debit
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- Definition

Amount of cash outflow for payment of an obligation from a lender, including but not limited to, letter of credit, standby letter of credit and revolving credit arrangements.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
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-Name Accounting Standards Codification
-Topic 235
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-Section S99
-Paragraph 1
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-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

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Debt - Mortgage Payable - Additional Information (Details)		3 Months Ended		9 Months Ended	12 Months Ended
	Nov. 09, 2017 USD ($)	Sep. 30, 2019 USD ($) property	Jun. 30, 2019 USD ($)	Sep. 30, 2019 USD ($) property loan	Dec. 31, 2012 USD ($)	Dec. 31, 2018 USD ($) property
Debt Instrument [Line Items]
Number of properties collateralized \| property		41		41		43
Interest Rate Swaps
Debt Instrument [Line Items]
Derivative, notional amount		$ 156,000,000.0		$ 156,000,000.0
Derivative weighted average interest rate		2.43%		2.43%
Mortgages
Debt Instrument [Line Items]
Scheduled principal payment				$ 4,600,000
Prepayment of line of credit			$ 49,000,000.0
Mortgages \| Interest Rate Swaps
Debt Instrument [Line Items]
Derivative, notional amount		$ 91,500,000		$ 91,500,000
Derivative weighted average interest rate		2.74%		2.74%
Fund Portfolio \| Mortgages
Debt Instrument [Line Items]
Number of mortgage loans \| loan				4
Borrowings, amount		$ 118,300,000		$ 118,300,000
Fund IV \| Mortgages
Debt Instrument [Line Items]
Borrowings, amount		23,800,000		23,800,000
Loan amount drew down		18,900,000		18,900,000
Repayments of debt				38,200,000
Decrease in future availability of mortgage loan				3,900,000
Fund IV \| Mortgages \| BSP I
Debt Instrument [Line Items]
Increase (decrease) in mortgage loans				9,400,000
Fund IV \| Mortgages \| 717 North Michigan Avenue
Debt Instrument [Line Items]
Increase (decrease) in mortgage loans				9,900,000
Fund IV \| Mortgages Two
Debt Instrument [Line Items]
Repayments of debt				18,400,000
Fund III \| Mortgages
Debt Instrument [Line Items]
Repayments of debt				4,700,000
Increase (decrease) in mortgage loans				10,000,000.0
Outstanding mortgage loan amount		39,500,000		39,500,000
Fund III \| Mortgages One
Debt Instrument [Line Items]
Repayments of debt				9,800,000
Fund III \| Construction Loans
Debt Instrument [Line Items]
Loan amount drew down		8,700,000		8,700,000
Core Portfolio
Debt Instrument [Line Items]
Derivative, notional amount		587,261,000		587,261,000
Core Portfolio \| Interest Rate Swaps
Debt Instrument [Line Items]
Derivative, notional amount		155,400,000		155,400,000		$ 0.0
Core Portfolio \| Mortgages \| Brandywine Portfolio
Debt Instrument [Line Items]
Debt default, amount		$ 26,300,000		$ 26,300,000		$ 26,300,000
Debt instrument, maturity date				Jul. 01, 2016
Interest rate, stated percentage		6.00%		6.00%
Debt default interest		5.00%		5.00%
Claim amount exclusive of accruing interest, default interest, fees and costs	$ 33,000,000.0
Fund II \| New Market Tax Credit
Debt Instrument [Line Items]
Percentage of tax credits on qualifying invested equity loans		39.00%
Transfer of tax credit transactions to investors exchange amount					$ 5,200,000
Redemption of loan expiration period				7 years
Fund II \| New Market Tax Credit \| Other Income
Debt Instrument [Line Items]
Income recognized from tax credit transactions		$ 5,000,000.0
Fund II \| City Point Project \| New Market Tax Credit
Debt Instrument [Line Items]
Income recognized from tax credit transactions		$ 5,000,000.0
LIBOR \| Mortgages
Debt Instrument [Line Items]
Basis spread on variable rate				1.75%
LIBOR \| Fund Portfolio \| Mortgages
Debt Instrument [Line Items]
Basis spread on variable rate				1.65%
LIBOR \| Fund IV \| Mortgages
Debt Instrument [Line Items]
Basis spread on variable rate				2.35%
LIBOR \| Fund IV \| Mortgages \| Variable Rate Debt
Debt Instrument [Line Items]
Basis spread on variable rate				3.10%
LIBOR \| Fund III \| Mortgages
Debt Instrument [Line Items]
Basis spread on variable rate				0.50%
LIBOR \| Fund III \| Mortgages \| Variable Rate Debt \| Minimum
Debt Instrument [Line Items]
Basis spread on variable rate				3.10%
LIBOR \| Fund III \| Mortgages \| Variable Rate Debt \| Maximum
Debt Instrument [Line Items]
Basis spread on variable rate				4.65%
LIBOR \| Core Portfolio \| Variable Rate Debt \| Minimum
Debt Instrument [Line Items]
Basis spread on variable rate				1.50%
LIBOR \| Core Portfolio \| Variable Rate Debt \| Maximum
Debt Instrument [Line Items]
Basis spread on variable rate				1.90%