Accounting Policies and Interim Results (Details) (Northern Sante Fe Corporation)	Feb. 12, 2010
Northern Sante Fe Corporation
Business Acquisition [Line Items]
Acquired remaining outstanding shares, percentage	100.00%

In a business combination achieved in stages, this element represents the percentage aquired of the remaining equity interest in the acquiree not already owned.

No definition available.

Name:	bni_BusinessCombinationStepAcquisitionRemainingEquityInterestAcquiredPercentage
Namespace Prefix:	bni_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant