Supplemental cash flow information (Tables)

12 Months Ended

Dec. 31, 2016

Supplemental Cash Flow Elements [Abstract]

Schedule of supplemental cash flow information

A summary of supplemental cash flow information for each of the three years ending December 31, 2016 is presented in the following table (in millions).

	2016		2015		2014
Cash paid during the period for:
Income taxes	$	4,719	$	4,535	$	4,014
Interest:
Insurance and other businesses		555		346		360
Railroad, utilities and energy businesses		2,788		2,717		2,487
Finance and financial products businesses		389		403		465
Non-cash investing and financing activities:
Liabilities assumed in connection with business acquisitions		16,555		2,812		6,334
Equity securities exchanged in connection with business acquisitions		4,239		—		2,478
Treasury stock acquired in connection with business acquisition		—		—		400
Conversions and other exchanges of investments		4,154		1,597		—