Derivative Financial Instruments (Narrative) (Details)	3 Months Ended
Mar. 31, 2019 USD ($) derivative	Dec. 31, 2018 USD ($) derivative
Derivative [Line Items]
Interest rate cap notional value	$ 150,000,000
Notional amount	150,000,000	$ 150,000,000
Estimate that will be reclassified from AOCI as an increase to interest expense over the next twelve months	300,000
Interest rate cap [Member]
Derivative [Line Items]
Interest rate cap notional value	$ 150,000,000
Derivative cap interest rate	4.00%
Interest rate cap [Member] \| Maximum [Member]
Derivative [Line Items]
Derivative, basis spread on variable rate	1.70%
Interest rate cap [Member] \| Minimum [Member]
Derivative [Line Items]
Derivative, basis spread on variable rate	1.20%
Interest rate cap [Member] \| Cash flow hedging [Member]
Derivative [Line Items]
Number of interest rate cap transactions \| derivative	3	3
Interest rate cap, Maturity 5/4/2021 [Member]
Derivative [Line Items]
Derivative cap interest rate	4.00%
Notional amount	$ 50,000,000	$ 50,000,000
Interest rate cap, Maturity 4/1/2019 [Member]
Derivative [Line Items]
Derivative cap interest rate	4.00%
Notional amount	$ 50,000,000	50,000,000
Interest rate cap, Maturity 2/3/2020 [Member]
Derivative [Line Items]
Derivative cap interest rate	4.00%
Notional amount	$ 50,000,000	$ 50,000,000

Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

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

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- Definition

Nominal or face amount used to calculate payments on the derivative asset.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-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

Reference 2: 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 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1A
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5579245-113959

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- Definition

The percentage points added to the reference rate to compute the variable rate on the interest rate derivative.

+ References

No definition available.

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- Definition

Cap rate on an interest rate derivative such as an interest rate cap or collar. If market rates exceed the cap rate, a payment or receipt is triggered on the contract.

+ References

No definition available.

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- Definition

The estimated value of gains (losses), net anticipated to be transferred in the future from accumulated other comprehensive income into earnings.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 30
-Section 50
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=112277219&loc=d3e80845-113994

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- 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

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- Definition

Number of interest rate derivative instruments held by the entity at the reporting date.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1A
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-URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5579245-113959

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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-Section 50
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