Investments in Marketable Securities

12 Months Ended

Dec. 31, 2023

Investments, Debt and Equity Securities [Abstract]

INVESTMENTS IN MARKETABLE SECURITIES

Marketable securities consisted of the following at December 31:


			UNREALIZED		UNREALIZED		FAIR
2023	COST		GAINS		LOSSES		VALUE
Marketable debt securities
U.S. tax-exempt securities	$	312.5	$	1.2	$	3.0	$	310.7
U.S. taxable municipal / non-U.S. provincial bonds		244.9		.8		5.6		240.1
U.S. corporate securities		357.1		1.4		5.2		353.3
U.S. government securities		159.2		.6		1.7		158.1
Non-U.S. corporate securities		529.4		2.3		7.5		524.2
Non-U.S. government securities		141.0		1.5		1.3		141.2
Other debt securities		92.8		.3		2.5		90.6
Marketable equity securities		10.0				5.6		4.4
Total marketable securities	$	1,846.9	$	8.1	$	32.4	$	1,822.6


			UNREALIZED		UNREALIZED		FAIR
2022	COST		GAINS		LOSSES		VALUE
Marketable debt securities
U.S. tax-exempt securities	$	452.8	$	.5	$	8.2	$	445.1
U.S. taxable municipal / non-U.S. provincial bonds		191.6				10.8		180.8
U.S. corporate securities		262.5		.1		11.6		251.0
U.S. government securities		118.0		.1		3.1		115.0
Non-U.S. corporate securities		467.9				17.9		450.0
Non-U.S. government securities		78.9		.2		2.7		76.4
Other debt securities		99.4				4.7		94.7
Marketable equity securities		10.0				8.8		1.2
Total marketable securities	$	1,681.1	$	.9	$	67.8	$	1,614.2

The cost of marketable debt securities is adjusted for amortization of premiums and accretion of discounts to maturity. Amortization, accretion, interest and dividend income and realized gains and losses are included in investment income. The cost of securities sold is based on the specific identification method. Gross realized gains were $.9, $.5 and $2.1, and gross realized losses were $4.5, $2.3 and $.4 for the years ended December 31, 2023, 2022 and 2021, respectively.

Net realized gains (losses) on marketable equity securities were $3.2, $(5.2) and nil for the years ended December 31, 2023, 2022 and 2021, respectively.

Marketable debt securities with continuous unrealized losses and their related fair values were as follows:


At December 31,	2023				2022
	LESS THAN TWELVE MONTHS		TWELVE MONTHS OR GREATER		LESS THAN TWELVE MONTHS		TWELVE MONTHS OR GREATER
Fair value	$	289.0	$	798.5	$	889.2	$	608.4
Unrealized losses		1.6		25.2		21.5		37.5

The unrealized losses on marketable debt securities above were due to higher yields on certain securities. The Company did not identify any indicators of a credit loss in its assessments. Accordingly, no allowance for credit losses was recorded at December 31, 2023 and December 31, 2022. The Company does not currently intend, and it is more likely than not that it will not be required, to sell the investment securities before recovery of the unrealized losses. The Company expects that the contractual principal and interest will be received on the investment securities.

Contractual maturities on marketable debt securities at December 31, 2023 were as follows:


	AMORTIZED		FAIR
Maturities:	COST		VALUE
Within one year	$	488.3	$	482.5
One to five years		1,336.0		1,324.5
Six to ten years		.7		.6
More than ten years		11.9		10.6
	$	1,836.9	$	1,818.2