Income Taxes Income Tax Examination (Details)	12 Months Ended
Dec. 31, 2017
Income Tax Examination [Line Items]
Income Tax Examination, Description	All U.S. federal income tax returns of BNSF are closed for audit through the tax period ending February 12, 2010. BNSF is currently under examination for the period February 13 - December 31, 2010 and years 2011, 2012 and 2013.

A brief description of status of the tax examination, significant findings to date, and the entity's position with respect to the findings.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 15
-Subparagraph (d)(2)
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32718-109319

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