Discontinued Operations, Assets Held for Sale and Impairments Impairment (Details) $ in Thousands	12 Months Ended
Dec. 31, 2017 USD ($) a	Dec. 31, 2016 USD ($) a	Dec. 31, 2015 USD ($) a
Impairment Charges	$ 4,481	$ 18,018	$ 22,932
Acres of Land with Impairment Charge \| a	12	244	139
buildings [Member]
Impairment Charges	$ 859	$ 3,719	$ 3,406
Land [Member]
Impairment Charges	$ 3,622	$ 14,299	$ 19,526

Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 45
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=68055307&loc=d3e2420-110228

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585

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