Certain issued and outstanding junior subordinated notes pertaining to certain financial covenants.

No definition available.

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- Definition

Remaining Debt Securities Authorized by the Board

+ References

No definition available.

+ Details

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- Definition

The board of managers authorized additional debt securities for issuance

+ References

No definition available.

+ Details

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- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28551-108399

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400

+ Details

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Period Type:	instant

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-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

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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Period Type:	duration

- Details

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- Details

Name:	us-gaap_LongtermDebtTypeAxis=bni_SECDebtShelfRegistrationMember
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- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_JuniorSubordinatedDebtMember
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- Details

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- Details

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Debt Notes and Debentures (Details) - USD ($) $ in Millions	Apr. 30, 2020	Apr. 06, 2020	Mar. 31, 2020	Jul. 31, 2019	May 31, 2019
Corporate Debt Securities
Debt Instrument [Line Items]
The board of managers authorized additional debt securities for issuance					$ 2,250
SEC Debt Shelf Registration
Debt Instrument [Line Items]
Remaining Debt Securities Authorized by the Board			$ 1,675
Junior Subordinated Debt
Debt Instrument [Line Items]
Subordinated notes related to financial covenants			$ 500
Three Point Fifty Five Percent Debenture Due Feb 15 2050 \| Corporate Debt Securities
Debt Instrument [Line Items]
Debt Instrument, Face Amount				$ 825
Debt Instrument, Interest Rate, Stated Percentage				3.55%
Subsequent Event \| SEC Debt Shelf Registration
Debt Instrument [Line Items]
Remaining Debt Securities Authorized by the Board	$ 1,100
Subsequent Event \| Three Point Zero Five Percent Due February 15, 2051 \| Corporate Debt Securities
Debt Instrument [Line Items]
Debt Instrument, Face Amount		$ 575
Debt Instrument, Interest Rate, Stated Percentage		3.05%
Subsequent Event \| Three Point Six Percent Debenture Due September 1, 2020 \| Corporate Debt Securities
Debt Instrument [Line Items]
Debt Instrument, Face Amount	$ 250
Debt Instrument, Interest Rate, Stated Percentage	3.60%