Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Investment in marketable equity securities at cost	$ 73	$ 73
Investment securities available for sale at cost	9,726	9,215
Investment securities held to maturity at fair value	$ 9,457	$ 3,759
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	10,000,000	10,000,000
Class A Common Stock
Common stock, par value (in dollars per share)	$ 1	$ 1
Common stock, shares authorized (in shares)	16,000,000	16,000,000
Common stock, shares issued (in shares)	14,996,325	8,811,220
Common stock, shares outstanding (in shares)	14,996,325	8,811,220
Class B Common Stock
Common stock, par value (in dollars per share)	$ 1	$ 1
Common stock, shares authorized (in shares)	2,000,000	2,000,000
Common stock, shares issued (in shares)	1,005,185	1,005,185
Common stock, shares outstanding (in shares)	1,005,185	1,005,185