Assets Held For Sale (detail) $ in Thousands	Mar. 31, 2016 USD ($)
Assets Held For Sale Not Part Of Disposal Group Current [Abstract]
Assets Held For Sale	$ 5,025
Northwest Processing Facility [Member]
Assets Held For Sale Not Part Of Disposal Group Current [Abstract]
Assets Held For Sale	$ 5,000
Assets Percentage	0.60%

Amount of other assets held-for-sale that are not part of a disposal group, expected to be sold within a year or the normal operating cycle, if longer.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 15
-Paragraph 4
-Subparagraph (b)(2)
-URI http://asc.fasb.org/extlink&oid=6390208&loc=d3e400-110220

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