Income Taxes (Tables)

12 Months Ended

Dec. 31, 2024

Income Tax Disclosure [Abstract]

Composition of income tax expense (benefit) included in consolidated statement of income and shareholders' equity [Table Text Block]

The following table presents the components of income tax expense (benefit) included in the amounts reported in the Company’s consolidated financial statements:

(for the year ended December 31, in millions)	2024		2023		2022
Composition of income tax expense included in the consolidated statement of income
Current expense:
Federal	$	1,252	$	477	$	636
Foreign	70		20		97
State	14		7		8
Total current tax expense	1,336		504		741
Deferred expense (benefit):
Federal	(152)		(163)		(186)
Foreign	(3)		39		(43)
Total deferred tax benefit	(155)		(124)		(229)
Total income tax expense included in the consolidated  statement of income	1,181		380		512
Composition of income tax expense (benefit) included  in shareholders’ equity
Expense (benefit) relating to changes in the unrealized gain (loss) on investments, unrealized loss on foreign exchange and other items in other comprehensive income (loss)	(79)		520		(2,002)
Total income tax expense (benefit) included in the  consolidated financial statements	$	1,102	$	900	$	(1,490)

Effective tax rate [Table Text Block]

The following is a reconciliation of income tax expense at the U.S. federal statutory income tax rate to the income tax expense reported in the Company’s consolidated statement of income:

(for the year ended December 31, in millions)	2024			2023			2022
Income before income taxes
U.S.	$	5,947		$	3,122		$	3,101
Foreign	233			249			253
Total income before income taxes	6,180			3,371			3,354
Effective tax rate
Statutory tax rate	21		%	21		%	21		%
Expected federal income tax expense	1,298			708			704
Tax effect of:
Nontaxable investment income	(122)			(132)			(149)
Audit reserve	9			(205)			(40)
Other, net	(4)			9			(3)
Total income tax expense	$	1,181		$	380		$	512
Effective tax rate	19		%	11		%	15		%

Deferred tax assets and liabilities [Table Text Block]

The net deferred tax asset comprises the tax effects of temporary differences related to the following assets and liabilities:

(at December 31, in millions)	2024		2023
Deferred tax assets
Investments	$	659	$	532
Claims and claim adjustment expense reserves	708		665
Unearned premium reserves	833		772
Internally developed software	303		204
Other	261		258
Total gross deferred tax assets	2,764		2,431
Less: valuation allowance	38		35
Adjusted gross deferred tax assets	2,726		2,396
Deferred tax liabilities
Deferred acquisition costs	673		627
Intangibles	87		70
Depreciation	118		125
Other	86		70
Total gross deferred tax liabilities	964		892
Net deferred tax asset	$	1,762	$	1,504

Net operating loss amounts by jurisdiction and year of expiration [Table Text Block]

The NOL amounts by jurisdiction and year of expiration are as follows:

(in millions)	Amount		Year of  expiration
United States	$	63	2035-2036
Canada	$	147	2035-2044
Republic of Ireland	$	114	None
United Kingdom	$	189	None

Reconciliation of unrecognized tax benefits [Table Text Block]

The following is a reconciliation of the beginning and ending amount of unrecognized tax benefits for the years ended December 31, 2024 and 2023:

(in millions)	2024		2023
Balance at January 1	$	14	$	9
Additions for tax positions of prior years	1		3
Reductions for tax positions of prior years	(1)		—
Additions based on tax positions related to current year	4		3
Expiration of statute of limitations	(1)		(1)
Balance at December 31	$	17	$	14