Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Deferred tax assets:
Reserves not yet deducted for tax purposes	$ 4,950	$ 4,552
Employee compensation and benefits	343	335
Net operating loss and tax credit carryforwards	464	466
Capitalized developed software	1,084	743
Other	853	723
Gross deferred tax assets	7,694	6,819
Valuation allowance	(655)	(614)
Deferred tax assets after valuation allowance	7,039	6,205
Deferred tax liabilities:
Intangibles and fixed assets	673	683
Deferred revenue	0	62
Deferred interest	113	114
Other	579	566
Gross deferred tax liabilities	1,365	1,425
Net deferred tax assets	$ 5,674	$ 4,780