Investments in Marketable Securities (Tables)

6 Months Ended

Jun. 30, 2025

Investments, Debt and Equity Securities [Abstract]

Marketable Securities

Marketable securities at June 30, 2025 and December 31, 2024 consisted of the following:


						UNREALIZED				UNREALIZED				FAIR
At June 30, 2025		COST				GAINS				LOSSES				VALUE
Marketable debt securities
U.S. tax-exempt securities		$	379.7			$	2.3			$	.1			$	381.9
U.S. taxable municipal / non-U.S. provincial bonds			403.3				3.6				.6				406.3
U.S. corporate securities			892.9				7.4				.8				899.5
U.S. government securities			208.7				1.8				.2				210.3
Non-U.S. corporate securities			613.0				5.7				.4				618.3
Non-U.S. government securities			195.8				3.0				.1				198.7
Other debt securities			192.6				1.4				.5				193.5
Marketable equity securities			10.0								4.8				5.2
Total marketable securities		$	2,896.0			$	25.2			$	7.5			$	2,913.7


						UNREALIZED				UNREALIZED				FAIR
At December 31, 2024		COST				GAINS				LOSSES				VALUE
Marketable debt securities
U.S. tax-exempt securities		$	304.5			$	.6			$	1.4			$	303.7
U.S. taxable municipal / non-U.S. provincial bonds			381.1				1.2				2.2				380.1
U.S. corporate securities			864.3				3.1				3.2				864.2
U.S. government securities			287.1				.1				1.5				285.7
Non-U.S. corporate securities			606.6				3.5				2.0				608.1
Non-U.S. government securities			163.5				1.4				.6				164.3
Other debt securities			166.4				.8				.8				166.4
Marketable equity securities			10.0								3.7				6.3
Total marketable securities		$	2,783.5			$	10.7			$	15.4			$	2,778.8

Marketable Debt Securities Continuous Unrealized Losses

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


		June 30, 2025								December 31, 2024
		LESS THAN				TWELVE MONTHS				LESS THAN				TWELVE MONTHS
		TWELVE MONTHS				OR GREATER				TWELVE MONTHS				OR GREATER
Fair value		$	238.6			$	164.5			$	932.9			$	365.5
Unrealized losses			.3				2.4				5.5				6.2

Contractual Maturities of Debt Securities

Contractual maturities of marketable debt securities at June 30, 2025 were as follows:


		AMORTIZED				FAIR
		COST				VALUE
Within one year		$	573.7			$	574.8
One to five years			2,306.7				2,328.6
Six to ten years			.7				.7
More than ten years			4.9				4.4
		$	2,886.0			$	2,908.5