Investments in Marketable Securities (Tables)

6 Months Ended

Jun. 30, 2023

Investments, Debt and Equity Securities [Abstract]

Marketable Securities

Marketable securities at June 30, 2023 and December 31, 2022 consisted of the following:

			UNREALIZED		UNREALIZED		FAIR
At June 30, 2023	COST		GAINS		LOSSES		VALUE
Marketable debt securities
U.S. tax-exempt securities	$	333.2	$	.1	$	6.2	$	327.1
U.S. taxable municipal / non-U.S. provincial bonds		230.2				9.7		220.5
U.S. corporate securities		309.4		.1		10.4		299.1
U.S. government and agency securities		150.6				4.0		146.6
Non-U.S. corporate securities		500.8				16.9		483.9
Non-U.S. government securities		113.4		.1		3.2		110.3
Other debt securities		104.5				4.4		100.1
Marketable equity securities		10.0				7.1		2.9
Total marketable securities	$	1,752.1	$	.3	$	61.9	$	1,690.5

			UNREALIZED		UNREALIZED		FAIR
At December 31, 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 and agency 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

Marketable Debt Securities Continuous Unrealized Losses

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

	June 30, 2023				December 31, 2022
	LESS THAN		TWELVE MONTHS		LESS THAN		TWELVE MONTHS
	TWELVE MONTHS		OR GREATER		TWELVE MONTHS		OR GREATER
Unrealized losses	$	14.7	$	40.1	$	21.5	$	37.5
Fair value		772.3		764.9		889.2		608.4

Contractual Maturities of Debt Securities

Contractual maturities of marketable debt securities at June 30, 2023 were as follows:

	AMORTIZED		FAIR
	COST		VALUE
Within one year	$	440.9	$	433.8
One to five years		1,287.4		1,241.6
Six to ten years		1.3		1.3
More than ten years		12.5		10.9
	$	1,742.1	$	1,687.6