Debt (Issuance and Sale of 6.375% Senior Notes Due 2022) (Details) (USD $)	0 Months Ended	3 Months Ended
Mar. 09, 2012	Mar. 31, 2012
Senior Notes 6.375% Due 2022
Debt Instrument
Interest rate on debt instrument (as a percent)	6.375%	6.375%
Aggregate principal amount of debt issued	$ 600,000,000
Net proceeds from issuance long-term debt	589,500,000
Redemption percentage, maximum (as a percent)		35.00%
Senior notes redemption price percentage of principal (as a percent)		106.375%
Debt instrument redemption price percentage of principal amount plus make whole premium and accrued and unpaid interest		100.00%
Reduced credit facility borrowing base per dollar of senior notes issued		$ 0.25
10.25% Senior notes due 2014
Debt Instrument
Interest rate on debt instrument (as a percent)		10.25%
6.75% Senior notes due 2020
Debt Instrument
Interest rate on debt instrument (as a percent)		6.75%
March 15, 2017 through March 14, 2018 \| Senior Notes 6.375% Due 2022
Senior Notes, Expressed As Percentage Of Principal Amount Redeemed, Plus Accured and Unpaid Interest
Redemption price, as a percentage of the principal or face amount of the given debt instrument, that the Company must pay upon redemption		103.188%
March 15, 2018 through March 14, 2019 \| Senior Notes 6.375% Due 2022
Senior Notes, Expressed As Percentage Of Principal Amount Redeemed, Plus Accured and Unpaid Interest
Redemption price, as a percentage of the principal or face amount of the given debt instrument, that the Company must pay upon redemption		102.125%
March 15, 2019 through March 14, 2020 \| Senior Notes 6.375% Due 2022
Senior Notes, Expressed As Percentage Of Principal Amount Redeemed, Plus Accured and Unpaid Interest
Redemption price, as a percentage of the principal or face amount of the given debt instrument, that the Company must pay upon redemption		101.063%
March 15, 2020 and thereafter \| Senior Notes 6.375% Due 2022
Senior Notes, Expressed As Percentage Of Principal Amount Redeemed, Plus Accured and Unpaid Interest
Redemption price, as a percentage of the principal or face amount of the given debt instrument, that the Company must pay upon redemption		100.00%
Minimum redemption notice at stipulated date and rate \| Senior Notes 6.375% Due 2022
Senior Notes, Expressed As Percentage Of Principal Amount Redeemed, Plus Accured and Unpaid Interest
Notice period range (in days)		30 days
Maximum redemption notice at stipulated date and rate \| Senior Notes 6.375% Due 2022
Senior Notes, Expressed As Percentage Of Principal Amount Redeemed, Plus Accured and Unpaid Interest
Notice period range (in days)		60 days

Represents the maximum amount of the given debt instrument the Company may redeem before the given date.

No definition available.

Name:	bry_DebtInstrumentRedemptionPercentageMaximum
Namespace Prefix:	bry_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the percentage of principal or face amount of the given debt instrument that the Company would pay, in addition to accrued and unpaid interest and a "make whole" premium, in order to redeem the given debt instrument in whole or in part.

+ References

No definition available.

+ Details

Name:	bry_DebtInstrumentRedemptionPricePercentageOfPrincipalAmountPlusMakeWholePremiumAndAccruedAndUnpaidInterest
Namespace Prefix:	bry_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the reduced borrowing base of the credit facility per dollar of additional debt issued

+ References

No definition available.

+ Details

Name:	bry_ReducedCreditFacilityBorrowingBasePerDollarOfSeniorNotesIssued
Namespace Prefix:	bry_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	bry_SeniorNotesExpressedAsPercentageOfPrincipalAmountRedeemedPlusAccuredAndUnpaidInterestAbstract
Namespace Prefix:	bry_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the redemption price, as a percentage of the principal or face amount of the given debt instrument, that the Company must pay upon redemption.

+ References

No definition available.

+ Details

Name:	bry_SeniorNotesRedemptionPriceExpressedAsPercentageOfPrincipalAmountRedeemed
Namespace Prefix:	bry_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Senior Notes Redemption Price, Notice Period in Days

+ References

No definition available.

+ Details

Name:	bry_SeniorNotesRedemptionPriceNoticePeriodRangeInDays
Namespace Prefix:	bry_
Data Type:	us-types:durationStringItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the redemption price, as a percentage of the principal or face amount of the given debt instrument, that the Company must pay upon redemption before the given date.

+ References

No definition available.

+ Details

Name:	bry_SeniorNotesRedemptionPricePercentageOfPrincipal
Namespace Prefix:	bry_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The stated principal amount of the debt instrument at time of issuance, which may vary from the carrying amount because of unamortized premium or discount.

+ References

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

-Publisher AICPA

-Name Accounting Principles Board Opinion (APB)

-Number 21

-Paragraph 16, 20

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 55

-Paragraph 8

-URI http://asc.fasb.org/extlink&oid=6584090&loc=d3e28878-108400

+ Details

Name:	us-gaap_DebtInstrumentFaceAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Interest rate stated in the contractual debt agreement.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22(a)(1))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	us-gaap_DebtInstrumentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The cash inflow from additional borrowings, net of cash paid to third parties in connection with debt origination.

+ References

No definition available.

+ Details

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