Consolidated Balance Sheet (Parenthetical) - shares	Mar. 31, 2016	Dec. 31, 2015
General partner—Phillips 66 units issued	1,691,850	1,683,425
General partner—Phillips 66 units outstanding	1,691,850	1,683,425
Common Units [Member] \| Public [Member]
Units issued	24,138,750	24,138,750
Units outstanding	24,138,750	24,138,750
Common Units [Member] \| Non-public [Member] \| Phillips 66 [Member]
Units issued	58,761,865	58,349,042
Units outstanding	58,761,865	58,349,042

The number of limited partner units outstanding.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 5
-Subparagraph (SAB TOPIC 4.F)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187171-122770

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 272
-SubTopic 10
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70434-108055

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Staff Accounting Bulletin (SAB)
-Number Topic 4
-Section F

Name:	us-gaap_LimitedPartnersCapitalAccountUnitsOutstanding
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant