Net Investment Income (Tables)

12 Months Ended

Dec. 31, 2024

Net Investment Income [Abstract]

Schedule of Net Investment Income

Net investment income includes interest and earnings on the following investments:

	Year ended December 31,
	2024			2023			2022
	(in millions)
Deposits and other investments	$	282.3		$	303.5		$	142.3
Debt securities		244.6			231.7			206.1
Deferred compensation plan assets		19.5			21.9			(25.3	)
Dividends on equity securities		10.4			10.5			9.0
Equity in earnings of affiliates, net		7.4			5.4			11.0
		564.2			573.0			343.1
Investment expenses		(3.2	)		(3.0	)		(3.0	)
Net investment income	$	561.0		$	570.0		$	340.1