Investments in debt and equity securities

We have investments in certain debt and equity securities, primarily at Insurance Services, that have been classified as available-for-sale and recorded at fair value. In addition, Insurance Services has an equity security investment in a real estate investment trust (REIT) which is recorded at fair value based on the net asset value (NAV) of the investment. These investments are primarily included in Other assets in Statement 3. Unrealized gains and losses arising from the revaluation of debt and equity securities are included, net of applicable deferred income taxes, in equity (Accumulated other comprehensive income (loss) in Statement 3). Realized gains and losses on sales of investments are generally determined using the specific identification method for debt and equity securities and are included in Other income (expense) in Statement 1.

The cost basis and fair value of debt and equity securities were as follows:



	December 31, 2017							December 31, 2016
(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	$	10	$	—		$	10	$	9	$	—		$	9
Other U.S. and non-U.S. government bonds	42		—			42		60		—			60

Corporate bonds
Corporate bonds	585		(1		)	584		489		3			492
Asset-backed securities	67		—			67		90		—			90

Mortgage-backed debt securities
U.S. governmental agency	265		(4		)	261		225		(2		)	223
Residential	8		—			8		10		—			10
Commercial	17		—			17		36		—			36

Equity securities
Large capitalization value	287		(3		)	284		280		32			312
Real estate investment trust (REIT)	104		6			110		77		2			79
Smaller company growth	40		16			56		41		15			56
Total	$	1,425	$	14		$	1,439	$	1,317	$	50		$	1,367



Available-for-sale investments in an unrealized loss position that are not other-than-temporarily impaired:
	December 31, 2017
	Less than 12 months¹				12 months or more¹				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



	December 31, 2016
	Less than 12 months¹				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	$	131	$	1	$	13	$	—	$	144	$	1
Mortgage-backed debt securities
U.S. governmental agency	167		2		11		—		178		2
Equity securities
Large capitalization value	68		6		11		2		79		8
Smaller company growth	10		1		3		1		13		2
Total	$	376	$	10	$	38	$	3	$	414	$	13


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

Corporate Bonds. The unrealized losses on our investments in corporate bonds relate to changes in interest rates and credit-related yield spreads since time of purchase. We do not intend to sell the investments and it is not likely that we will be required to sell the investments before recovery of their amortized cost basis. We do not consider these investments to be other-than-temporarily impaired as of December 31, 2017.

Mortgage-Backed Debt Securities. The unrealized losses on our investments in U.S. governmental agency mortgage-backed securities relate to changes in interest rates and credit-related yield spreads since time of purchase. We do not intend to sell the investments and it is not likely that we will be required to sell the investments before recovery of their amortized cost basis. We do not consider these investments to be other-than-temporarily impaired as of December 31, 2017.

Equity Securities. The unrealized losses on our investments in equity securities relate to inherent risks of individual holdings and/or their respective sectors. We do not consider these investments to be other-than-temporarily impaired as of December 31, 2017.

The cost basis and fair value of the available-for-sale debt securities at December 31, 2017, by contractual maturity, is shown below. Expected maturities will differ from contractual maturities because borrowers may have the right to prepay and creditors may have the right to call obligations.




	December 31, 2017
(Millions of dollars)	Cost Basis		Fair Value
Due in one year or less	$	144	$	144
Due after one year through five years	418		417
Due after five years through ten years	121		120
Due after ten years	21		22
U.S. governmental agency mortgage-backed securities	265		261
Residential mortgage-backed securities	8		8
Commercial mortgage-backed securities	17		17
Total debt securities – available-for-sale	$	994	$	989




Sales of Securities:
	Years Ended December 31,
(Millions of dollars)	2017		2016		2015
Proceeds from the sale of available-for-sale securities	$	930	$	694	$	351
Gross gains from the sale of available-for-sale securities	$	109	$	55	$	64
Gross losses from the sale of available-for-sale securities	$	5	$	4	$	2