Investments (Tables)

9 Months Ended

Sep. 30, 2017

Investments

Summary of the amortized cost and estimated fair value of short-term investments classified as trading securities

	September 30, 2017				December 31, 2016
	Amortized		Fair		Amortized		Fair
(Millions of dollars)	Cost		Value		Cost		Value
Domestic equity securities	$	609	$	716	$	444	$	482
Foreign equity securities		265		310		198		199
Domestic debt securities held in mutual funds/ETFs/U.S. Treasuries		174		175		437		437
High yield securities		85		86		114		115
Money market funds held in trading accounts		36		36		13		13
Collateralized loan obligations		28		29		25		26
Other trading securities		4		6		5		5
Total trading short-term investments	$	1,201	$	1,358	$	1,236	$	1,277