Reorganization items, net (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Discontinued Operations and Disposal Groups [Abstract]
Reorganization items, net	$ (740)	$ (21)	$ (1,041)	$ (2,849)
Payments for reorganization items	$ 300	$ 900	$ 600	$ 4,700

Amount of gain (loss) on settlement of other claims for entities not in bankruptcy, reported as a reorganization item.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 852
-SubTopic 10
-Section 55
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=84165509&loc=d3e56145-112766

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 852
-SubTopic 10
-Section 45
-Paragraph 9
-URI http://asc.fasb.org/extlink&oid=114872137&loc=d3e55730-112764

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration