Carrying amount as of the balance sheet date of known and reasonably estimable amounts of recoveries from third-parties pertaining to an entity's environmental remediation obligations. An entity's balance sheet may include several assets that relate to an environmental remediation obligation. Among them are the following: a. Receivables from other potentially responsible parties that are not providing initial funding; b. anticipated recoveries from insurers; and c. anticipated recoveries from prior owners as a result of indemnification agreements.

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

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 410

-SubTopic 30

-Section 45

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6393211&loc=d3e13022-110858

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

Commitments and Contingencies (Details) (USD $) In Millions, unless otherwise specified			2 Months Ended
	Sep. 30, 2013 DPM	Sep. 30, 2013 DPTS	Aug. 31, 2013 Derailment of freight train item	Jul. 06, 2013 Derailment of freight train bbl item	Sep. 30, 2013 Derailment of freight train Accrued expenses and other current liabilities	Sep. 30, 2013 Derailment of freight train Other current assets
Lac-Megantic, Quebec
Membership interest in joint venture (as a percent)	50.00%	50.00%
Number of tanker-cars carried by the freight train				72
Volume of crude oil (in barrels)				50,000
Number of complaints filed			20
Liabilities recorded based on estimated losses					$ 14.2
Receivables for portion of liability recoverable from insurance						$ 13.4