Fair Value Measurements (Tables)

6 Months Ended

Jun. 30, 2025

Fair Value Disclosures [Abstract]

Fair Value of Assets Measured on Recurring Basis

The following tables present the fair values of the Company’s assets, measured on a recurring basis, as of June 30, 2025 and December 31, 2024:

(in millions)	Total		Level 1		Level 2		Level 3
June 30, 2025
Debt securities:
U.S. Treasury bonds	$	170.2	$	—	$	170.2	$	—
Municipal bonds		876.7		—		876.7		—
Foreign government bonds		225.5		—		225.5		—
Governmental agency bonds		206.3		—		206.3		—
Governmental agency mortgage-backed securities		5,037.9		—		5,037.9		—
U.S. corporate debt securities		1,010.0		—		1,010.0		—
Foreign corporate debt securities		492.3		—		492.3		—
		8,018.9		—		8,018.9		—
Equity securities:
Common stocks		384.2		384.2		—		—
Preferred stocks		11.8		11.8		—		—
		396.0		396.0		—		—
Total	$	8,414.9	$	396.0	$	8,018.9	$	—

(in millions)	Total		Level 1		Level 2		Level 3
December 31, 2024
Debt securities:
U.S. Treasury bonds	$	175.6	$	—	$	175.6	$	—
Municipal bonds		776.5		—		776.5		—
Foreign government bonds		211.6		—		211.6		—
Governmental agency bonds		189.8		—		189.8		—
Governmental agency mortgage-backed securities		4,502.3		—		4,502.3		—
U.S. corporate debt securities		925.6		—		925.6		—
Foreign corporate debt securities		484.5		—		484.5		—
		7,265.9		—		7,265.9		—
Equity securities:
Common stocks		374.7		374.7		—		—
Preferred stocks		12.1		12.1		—		—
		386.8		386.8		—		—
Total	$	7,652.7	$	386.8	$	7,265.9	$	—

Carrying Amounts and Estimated Fair Values of Financial Instruments Not Measured at Fair Value

The following table presents the carrying amounts and estimated fair values of the Company’s financial instruments not measured at fair value as of June 30, 2025 and December 31, 2024:

	Carrying		Estimated fair value
(in millions)	Amount		Total		Level 1		Level 2		Level 3
June 30, 2025
Assets:
Cash and cash equivalents	$	2,031.2	$	2,031.2	$	2,031.2	$	—	$	—
Deposits with banks	$	82.7	$	82.5	$	13.8	$	68.7	$	—
Notes receivable, net	$	41.1	$	41.9	$	—	$	—	$	41.9
Secured financings receivable	$	975.1	$	975.1	$	—	$	975.1	$	—
Liabilities:
Secured financings payable	$	883.8	$	883.8	$	—	$	883.8	$	—
Notes and contracts payable	$	1,546.8	$	1,436.7	$	—	$	1,426.4	$	10.3

	Carrying		Estimated fair value
(in millions)	Amount		Total		Level 1		Level 2		Level 3
December 31, 2024
Assets:
Cash and cash equivalents	$	1,718.1	$	1,718.1	$	1,718.1	$	—	$	—
Deposits with banks	$	85.4	$	85.3	$	20.7	$	64.6	$	—
Notes receivable, net	$	34.4	$	34.6	$	—	$	—	$	34.6
Secured financings receivable	$	690.0	$	690.0	$	—	$	690.0	$	—
Liabilities:
Secured financings payable	$	643.8	$	643.8	$	—	$	643.8	$	—
Notes and contracts payable	$	1,546.6	$	1,399.4	$	—	$	1,388.4	$	11.0