Investment Securities (Details 1) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Debt Securities, Available-for-sale [Line Items]
Estimated fair value, less than 12 months	$ 1,503	$ 4,311
Gross unrealized losses, less than 12 months	(14)	(83)
Estimated fair value, 12 months or more	2,153	52
Gross unrealized losses, more than 12 months	(45)	(1)
State and municipal obligations
Debt Securities, Available-for-sale [Line Items]
Estimated fair value, less than 12 months	0	52
Gross unrealized losses, less than 12 months	0	(10)
Estimated fair value, 12 months or more	31	0
Gross unrealized losses, more than 12 months	(8)	0
U.S. Government treasury obligations
Debt Securities, Available-for-sale [Line Items]
Estimated fair value, less than 12 months	982	3,710
Gross unrealized losses, less than 12 months	(13)	(72)
Estimated fair value, 12 months or more	2,122	52
Gross unrealized losses, more than 12 months	(37)	(1)
Foreign government bonds and obligations
Debt Securities, Available-for-sale [Line Items]
Estimated fair value, less than 12 months	521	549
Gross unrealized losses, less than 12 months	(1)	(1)
Estimated fair value, 12 months or more	0	0
Gross unrealized losses, more than 12 months	$ 0	$ 0