Derivative effective month year.

No definition available.

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- Definition

Derivative maturity month year.

+ References

No definition available.

+ Details

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- 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

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- Definition

Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and not elected to be offset.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 55
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=99393222&loc=SL20226008-175313

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=109250915&loc=d3e13433-108611

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312

+ Details

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Balance Type:	debit
Period Type:	instant

- Definition

Fair value of the assets less the liabilities of a derivative or group of derivatives.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=109250915&loc=d3e13433-108611

+ Details

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Balance Type:	debit
Period Type:	instant

- Definition

Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities not subject to a master netting arrangement and not elected to be offset.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=109250915&loc=d3e13433-108611

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 55
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=99393222&loc=SL20226008-175313

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Variable interest rate in effect as of the balance sheet date related to the interest rate derivative.

+ References

No definition available.

+ Details

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Data Type:	num:percentItemType
Balance Type:	na
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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Financial Instruments and Fair Value Measurements - Schedule of Derivative Financial Instruments (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Jul. 31, 2018	Dec. 31, 2017
Derivatives, Fair Value [Line Items]
Fair value, liability derivatives	$ (361)		$ (1,467)
Fair value, asset derivatives	15,115		4,402
Interest Rate Swaps
Derivatives, Fair Value [Line Items]
Aggregate Notional Amount	50,000
Core Portfolio
Derivatives, Fair Value [Line Items]
Aggregate Notional Amount	397,510
Fair value, derivatives, net	$ 12,394		2,638
Core Portfolio \| Interest Rate Swaps
Derivatives, Fair Value [Line Items]
Aggregate Notional Amount		$ 125,000
Derivative Effective Date	2020-07
Fair value, liability derivatives	$ (900)
Core Portfolio \| Interest Rate Swaps \| Other Liabilities
Derivatives, Fair Value [Line Items]
Aggregate Notional Amount	$ 11,176
Derivative Effective Date	2012-12
Derivative Maturity Date	2022-12
Fair value, liability derivatives	$ (361)		(1,438)
Core Portfolio \| Interest Rate Swaps \| Other Assets
Derivatives, Fair Value [Line Items]
Aggregate Notional Amount	386,334
Fair value, asset derivatives	$ 12,755		4,076
Core Portfolio \| Interest Rate Swaps \| Minimum \| Other Liabilities
Derivatives, Fair Value [Line Items]
Strike Rate	3.77%
Core Portfolio \| Interest Rate Swaps \| Minimum \| Other Assets
Derivatives, Fair Value [Line Items]
Derivative Effective Date	2013-02
Derivative Maturity Date	2018-11
Strike Rate	1.24%
Core Portfolio \| Interest Rate Swaps \| Maximum \| Other Liabilities
Derivatives, Fair Value [Line Items]
Strike Rate	3.77%
Core Portfolio \| Interest Rate Swaps \| Maximum \| Other Assets
Derivatives, Fair Value [Line Items]
Derivative Effective Date	2020-07
Derivative Maturity Date	2030-07
Strike Rate	3.77%
Fund Portfolio \| Fund II
Derivatives, Fair Value [Line Items]
Aggregate Notional Amount	$ 19,385
Fair value, derivatives, net	287		(29)
Fund Portfolio \| Fund II \| Interest Rate Swaps \| Other Liabilities
Derivatives, Fair Value [Line Items]
Aggregate Notional Amount	$ 0
Derivative Effective Date	2014-10
Derivative Maturity Date	2021-11
Fair value, liability derivatives	$ 0		(29)
Fund Portfolio \| Fund II \| Interest Rate Swaps \| Other Assets
Derivatives, Fair Value [Line Items]
Aggregate Notional Amount	$ 19,385
Derivative Effective Date	2014-10
Derivative Maturity Date	2021-11
Fair value, asset derivatives	$ 287		0
Fund Portfolio \| Fund II \| Interest Rate Swaps \| Minimum \| Other Liabilities
Derivatives, Fair Value [Line Items]
Strike Rate	2.88%
Fund Portfolio \| Fund II \| Interest Rate Swaps \| Minimum \| Other Assets
Derivatives, Fair Value [Line Items]
Strike Rate	2.88%
Fund Portfolio \| Fund II \| Interest Rate Swaps \| Maximum \| Other Liabilities
Derivatives, Fair Value [Line Items]
Strike Rate	2.88%
Fund Portfolio \| Fund II \| Interest Rate Swaps \| Maximum \| Other Assets
Derivatives, Fair Value [Line Items]
Strike Rate	2.88%
Fund Portfolio \| Fund III \| Interest Rate Cap \| Other Assets
Derivatives, Fair Value [Line Items]
Aggregate Notional Amount	$ 58,000
Derivative Effective Date	2016-12
Derivative Maturity Date	2020-01
Fair value, asset derivatives	$ 39		14
Fund Portfolio \| Fund III \| Interest Rate Cap \| Minimum \| Other Assets
Derivatives, Fair Value [Line Items]
Strike Rate	3.00%
Fund Portfolio \| Fund III \| Interest Rate Cap \| Maximum \| Other Assets
Derivatives, Fair Value [Line Items]
Strike Rate	3.00%
Fund Portfolio \| Fund IV
Derivatives, Fair Value [Line Items]
Aggregate Notional Amount	$ 180,974
Fair value, derivatives, net	1,771		312
Fund Portfolio \| Fund IV \| Interest Rate Swaps \| Other Assets
Derivatives, Fair Value [Line Items]
Aggregate Notional Amount	72,074
Fair value, asset derivatives	$ 1,728		295
Fund Portfolio \| Fund IV \| Interest Rate Swaps \| Minimum \| Other Assets
Derivatives, Fair Value [Line Items]
Derivative Effective Date	2017-03
Derivative Maturity Date	2020-03
Strike Rate	1.82%
Fund Portfolio \| Fund IV \| Interest Rate Swaps \| Maximum \| Other Assets
Derivatives, Fair Value [Line Items]
Derivative Effective Date	2017-11
Derivative Maturity Date	2022-12
Strike Rate	2.11%
Fund Portfolio \| Fund IV \| Interest Rate Cap \| Other Assets
Derivatives, Fair Value [Line Items]
Aggregate Notional Amount	$ 108,900
Fair value, asset derivatives	$ 43		17
Fund Portfolio \| Fund IV \| Interest Rate Cap \| Minimum \| Other Assets
Derivatives, Fair Value [Line Items]
Derivative Effective Date	2016-07
Derivative Maturity Date	2019-08
Strike Rate	3.00%
Fund Portfolio \| Fund IV \| Interest Rate Cap \| Maximum \| Other Assets
Derivatives, Fair Value [Line Items]
Derivative Effective Date	2016-11
Derivative Maturity Date	2019-12
Strike Rate	3.00%
Fund Portfolio \| Fund V
Derivatives, Fair Value [Line Items]
Aggregate Notional Amount	$ 86,570
Fair value, derivatives, net	263		0
Fund Portfolio \| Fund V \| Interest Rate Swaps \| Other Assets
Derivatives, Fair Value [Line Items]
Aggregate Notional Amount	86,570
Fair value, asset derivatives	$ 263		$ 0
Fund Portfolio \| Fund V \| Interest Rate Swaps \| Minimum \| Other Assets
Derivatives, Fair Value [Line Items]
Derivative Effective Date	2018-01
Derivative Maturity Date	2021-02
Strike Rate	2.41%
Fund Portfolio \| Fund V \| Interest Rate Swaps \| Maximum \| Other Assets
Derivatives, Fair Value [Line Items]
Derivative Effective Date	2018-06
Derivative Maturity Date	2023-06
Strike Rate	2.88%