Accounts receivable

12 Months Ended

Dec. 31, 2015

Accounts receivable

Accounts receivable

6– Accounts receivable

In millions	December 31,		2015		2014
Freight		$	705	$	777
Non-freight			180		160
Gross accounts receivable			885		937
Allowance for doubtful accounts			(7)		(9)
Net accounts receivable		$	878	$	928