Supplemental cash flow information (Tables)

12 Months Ended

Dec. 31, 2015

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, 2015 is presented in the following table (in millions).

	2015		2014		2013
Cash paid during the period for:
Income taxes	$	4,535	$	4,014	$	5,401
Interest:
Insurance and other businesses		346		360		343
Railroad, utilities and energy businesses		2,717		2,487		1,958
Finance and financial products businesses		403		465		573
Non-cash investing and financing activities:
Liabilities assumed in connection with business acquisitions		2,812		6,334		9,224
Equity securities exchanged in connection with business acquisitions		—		2,478		—
Treasury stock acquired in connection with business acquisition		—		400		—