Document and Entity Information	12 Months Ended
	Dec. 31, 2017 shares
Document Information [Line Items]
Document Type	20-F
Amendment Flag	false
Document Period End Date	Dec. 31, 2017
Document Fiscal Year Focus	2017
Document Fiscal Period Focus	FY
Entity Registrant Name	BP PLC
Entity Central Index Key	0000313807
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Current Reporting Status	Yes
Entity Well-known Seasoned Issuer	Yes
Ordinary Shares
Document Information [Line Items]
Entity Common Stock, Shares Outstanding	21,288,193,071
First Preference Shares
Document Information [Line Items]
Entity Common Stock, Shares Outstanding	7,232,838
Second Preference Shares
Document Information [Line Items]
Entity Common Stock, Shares Outstanding	5,473,414