Supplemental cash flow information (Tables)

6 Months Ended

Jun. 30, 2021

Supplemental Cash Flow Elements [Abstract]

Schedule of supplemental cash flow information

A summary of supplemental cash flow information is presented in the following table (in millions).

	First Six Months
	2021		2020
Cash paid during the period for:
Income taxes	$	2,508	$	980
Interest:
Insurance and other		699		591
Railroad, utilities and energy		1,580		1,438