Acquisitions and Dispositions - Property Dispositions (Details) $ in Thousands	3 Months Ended
Mar. 31, 2018 USD ($) property	Mar. 31, 2019 property_Unit
Business Acquisition [Line Items]
No. of Units \| property_Unit		10,008
Property dispositions
Business Acquisition [Line Items]
No. of Units \| property	1,161
Sales Price	$ 148,670
Gain on Sale	51,981
Non-controlling partner's portion of the gain	$ 25,140
Property dispositions \| Palm Beach Gardens, FL
Business Acquisition [Line Items]
No. of Units \| property	542
Sales Price	$ 97,200
Gain on Sale	41,830
Non-controlling partner's portion of the gain	$ 20,593
Property dispositions \| Valley, AL
Business Acquisition [Line Items]
No. of Units \| property	618
Sales Price	$ 51,000
Gain on Sale	9,712
Non-controlling partner's portion of the gain	$ 4,547
Property dispositions \| Fort Washington
Business Acquisition [Line Items]
No. of Units \| property	1
Sales Price	$ 470
Gain on Sale	439
Non-controlling partner's portion of the gain	$ 0

Amount after tax of income (loss) from a discontinued operation including the portion attributable to the noncontrolling interest. Includes, but is not limited to, the income (loss) from operations during the phase-out period, gain (loss) on disposal, gain (loss) for reversal of write-down (write-down) to fair value, less cost to sell, and adjustments to a prior period gain (loss) on disposal.

Amount after tax of income (loss) from a discontinued operation attributable to the noncontrolling interest. Includes, but is not limited to, the income (loss) from operations during the phase-out period, gain (loss) on disposal, gain (loss) for reversal of write-down (write-down) to fair value, less cost to sell, and adjustments to a prior period gain (loss) on disposal.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 50
-Paragraph 5B
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-URI http://asc.fasb.org/extlink&oid=64827811&loc=SL51721673-107760

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
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-Section 45
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-URI http://asc.fasb.org/extlink&oid=65878427&loc=d3e1012-107759

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
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-Section 45
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-URI http://asc.fasb.org/extlink&oid=96868048&loc=SL4569616-111683

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
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-URI http://asc.fasb.org/extlink&oid=96868048&loc=SL4568447-111683

Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
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Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 50
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-Publisher FASB
-Name Accounting Standards Codification
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-Publisher FASB
-Name Accounting Standards Codification
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-URI http://asc.fasb.org/extlink&oid=65878427&loc=d3e957-107759

+ Details