Document and Entity Information (USD $)	12 Months Ended
	Dec. 31, 2011	Jun. 30, 2011	Feb. 14, 2012 Class A	Feb. 14, 2012 Class B
Entity Registrant Name	BERRY PETROLEUM CO
Entity Central Index Key	0000778438
Document Type	10-K
Document Period End Date	Dec. 31, 2011
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Public Float		$ 2,583,421,226
Entity Common Stock, Shares Outstanding			52,150,685	1,797,784
Document Fiscal Year Focus	2011
Document Fiscal Period Focus	FY