Restructuring Costs (Tables)

12 Months Ended

Dec. 31, 2015

Restructuring Charges [Abstract]

Summary of separation activity

The following table summarizes the 2014 and 2015 employee separation activity:

(Millions of dollars)	Total
Liability balance at December 31, 2013	$	89
Increase in liability (separation charges)	382
Reduction in liability (payments)	(289		)
Liability balance at December 31, 2014	$	182
Increase in liability (separation charges)	641
Reduction in liability (payments)	(340		)
Liability balance at December 31, 2015	$	483