Investments in debt and equity securities (Tables)

12 Months Ended

Dec. 31, 2018

Investments, Debt and Equity Securities [Abstract]

Schedule of available-for-sale securities

	December 31, 2018							December 31, 2017
(Millions of dollars)	Cost Basis		Unrealized Pretax Net Gains (Losses)			Fair Value		Cost Basis		Unrealized Pretax Net Gains (Losses)			Fair Value
Government debt
U.S. treasury bonds	$	9	$	—		$	9	$	10	$	—		$	10
Other U.S. and non-U.S. government bonds	42		—			42		42		—			42
Corporate bonds
Corporate bonds	735		(15		)	720		585		(1		)	584
Asset-backed securities	63		—			63		67		—			67
Mortgage-backed debt securities
U.S. governmental agency	301		(4		)	297		265		(4		)	261
Residential	7		—			7		8		—			8
Commercial	14		(1		)	13		17		—			17
Total debt securities	$	1,171	$	(20	)	$	1,151	$	994	$	(5	)	$	989
Equity securities 1
Large capitalization value								287		(3		)	284
Real estate investment trust (REIT)								104		6			110
Smaller company growth								40		16			56
Total								$	431	$	19		$	450
1 Beginning January 1, 2018, the unrealized gains and losses arising from the revaluation of the equity securities are included in Other income (expense) in Statement 1. See Note 1J for additional information.

Investments in an unrealized loss position that are not other-than-temporarily impaired

Available-for-sale investments in an unrealized loss position that are not other-than-temporarily impaired:
	December 31, 2018
	Less than 12 months 1				12 months or more 1				Total
(Millions of dollars)	Fair Value		Unrealized Losses		Fair Value		Unrealized Losses		Fair Value		Unrealized Losses
Corporate bonds
Corporate bonds	$	280	$	3	$	391	$	11	$	671	$	14
Asset-backed securities	6		—		38		1		44		1
Mortgage-backed debt securities
U.S. governmental agency	52		—		223		5		275		5
Commercial	—		—		14		1		14		1
Total	$	338	$	3	$	666	$	18	$	1,004	$	21

	December 31, 2017
	Less than 12 months 1				12 months or more 1				Total
(Millions of dollars)	Fair Value		Unrealized Losses		Fair Value		Unrealized Losses		Fair Value		Unrealized Losses
Corporate bonds
Corporate bonds	$	312	$	2	$	38	$	—	$	350	$	2
Mortgage-backed debt securities
U.S. governmental agency	129		1		110		3		239		4
Equity securities
Large capitalization value	129		5		14		2		143		7
Smaller company growth	17		1		1		—		18		1
Total	$	587	$	9	$	163	$	5	$	750	$	14

¹  Indicates length of time that individual securities have been in a continuous unrealized loss position.

Cost basis and fair value of the available-for-sale debt securities by contractual maturity

	December 31, 2018
(Millions of dollars)	Cost Basis		Fair Value
Due in one year or less	$	139	$	139
Due after one year through five years	647		635
Due after five years through ten years	46		43
Due after ten years	17		17
U.S. governmental agency mortgage-backed securities	301		297
Residential mortgage-backed securities	7		7
Commercial mortgage-backed securities	14		13
Total debt securities – available-for-sale	$	1,171	$	1,151

Schedule of proceeds and gross gain and losses from the sale of available-for-sale securities

Sales of Securities:
	Years Ended December 31,
(Millions of dollars)	2018		1	2017		2016
Proceeds from the sale of available-for-sale securities	$	247		$	930	$	694
Gross gains from the sale of available-for-sale securities	$	—		$	109	$	55
Gross losses from the sale of available-for-sale securities	$	—		$	5	$	4
1 Beginning January 1, 2018, equity securities are no longer classified as available-for-sale securities.