CONSOLIDATED BALANCE SHEETS (Unaudited) (Parenthetical) - USD ($) $ in Thousands, shares in Millions	Mar. 31, 2024	Dec. 31, 2023
Statement of Financial Position [Abstract]
Trading investments, cost	$ 44,978	$ 43,412
Available-for sale investments at fair value, cost	2,423,183	2,563,984
Allowance for credit losses	$ 1,350,058	$ 1,339,772
Preferred stock, par or stated value (in dollars per share)	$ 0.20	$ 0.20
Preferred stock, shares authorized (in shares)	20.0	20.0
Preferred stock, shares issued (in shares)	2.5	2.5
Preferred stock, liquidation preference (in dollars per share)	$ 100	$ 100
Common stock, par value (in dollars per share)	$ 0.20	$ 0.20
Common stock, shares authorized (in shares)	1,125.0	1,125.0
Common stock, shares issued (in shares)	440.2	438.2
Tax benefit on accumulated other comprehensive loss	$ 24,752	$ 24,176
Common stock held in treasury (in shares)	219.9	217.9