Impairment Charges (Details Textual) $ in Thousands	3 Months Ended	12 Months Ended
Jun. 30, 2017 property	Mar. 31, 2017 property	Dec. 31, 2016 property	Dec. 31, 2017 USD ($) property	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($) property
Property, Plant and Equipment [Abstract]
Impairments					$ 121	$ 686
Number of properties sold \| property	3	6	6	2		2
Impairment of real estate				$ 5,385		$ 3,639

Amount after tax of (gain) loss recognized for the (reversal of write-down) write-down to fair value, less cost to sell, of a discontinued operation.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 45
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=65878427&loc=d3e957-107759

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 45
-Paragraph 3B
-URI http://asc.fasb.org/extlink&oid=65878427&loc=SL51721525-107759

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 50
-Paragraph 5C
-Subparagraph (b)(2)
-URI http://asc.fasb.org/extlink&oid=64827811&loc=SL51721675-107760

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=64827811&loc=d3e1361-107760

Name:	us-gaap_DiscontinuedOperationProvisionForLossGainOnDisposalNetOfTax
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration