Gain on Sales of Real Estate (Details) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2018 USD ($) property	Jun. 30, 2017 USD ($) property	Jun. 30, 2018 USD ($) property	Jun. 30, 2017 USD ($) property
Gain (Loss) on Sale of Investments [Abstract]
Property Sales Count \| property	26	15	40	29
Proceeds from sales of real estate	$ 33,700	$ 12,800	$ 47,526	$ 44,005
Gain on sales of properties	$ 7,800	$ 2,800	$ 11,000	$ 13,400

The difference between the carrying value and the sale price of real estate or properties that were intended to be sold or held for capital appreciation or rental income. This element refers to the gain (loss) included in earnings and not to the cash proceeds of the sale. This element is a noncash adjustment to net income when calculating net cash generated by operating activities using the indirect method.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585

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