Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Deferred tax assets:
Reserves not yet deducted for tax purposes	$ 4,552	$ 4,052
Employee compensation and benefits	335	353
Net operating loss and tax credit carryforwards	466	411
Capitalized developed software	743	0
Other	723	776
Gross deferred tax assets	6,819	5,592
Valuation allowance	(614)	(537)
Deferred tax assets after valuation allowance	6,205	5,055
Deferred tax liabilities:
Intangibles and fixed assets	683	671
Deferred revenue	62	126
Deferred interest	114	118
Investment in joint ventures	0	17
Other	566	618
Gross deferred tax liabilities	1,425	1,550
Net deferred tax assets	$ 4,780	$ 3,505