Remediation Receivables (Details) - Paramount - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Recorded Third-Party Environmental Recoveries, Current	$ 623	$ 623
Recorded Third-Party Environmental Recoveries, Noncurrent	$ 2,374	$ 2,648

Cumulative amount of the asset for third-party recoveries related to environmental remediation obligations that is recoverable after one year from the balance sheet date.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 410
-SubTopic 30
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=6393242&loc=d3e13207-110859

Name:	us-gaap_RecordedThirdPartyEnvironmentalRecoveriesNoncurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant