Lawsuits, Claims, Commitments and Contingencies (Details) - Diamond Shamrock Chemicals Company - State of New Jersey Member - USD ($) $ in Millions	1 Months Ended
Jun. 30, 2015	Apr. 30, 2015	Feb. 28, 2015	Dec. 31, 2014
Lawsuits, commitments and contingencies
Litigation Settlement, Amount				$ 190
Payments related to settlement	$ 60	$ 60	$ 70

Amount of payments made reducing loss contingency liability.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 450

-SubTopic 20

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=25496072&loc=d3e14326-108349

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