CONSOLIDATED BALANCE SHEETS (Unaudited) (Parenthetical) - USD ($) $ in Thousands, shares in Millions	Jun. 30, 2023	Dec. 31, 2022
Statement of Financial Position [Abstract]
Trading investments, cost	$ 43,260	$ 47,554
Available-for sale investments at fair value, cost	2,563,816	2,554,332
Allowance for credit losses	$ 1,364,716	$ 1,357,075
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)	438.0	435.1
Tax benefit on accumulated other comprehensive loss	$ 26,845	$ 30,160
Common stock held in treasury (in shares)	211.9	194.4