CONSOLIDATED BALANCE SHEETS PARENTHETICAL - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Available for Sale at Fair value - Amortized cost	$ 46,753	$ 38,882
Preferred stock par value	$ 0.01	$ 0.01
Preferred stock shares authorized	10,000,000	10,000,000
Preferred stock shares issued	0	0
Preferred stock shares outstanding	0	0
Common stock par value	$ 0.01	$ 0.01
Common stock shares authorized	140,000,000	140,000,000
Common Stock, Shares, Issued	79,137,758	79,137,758
Common stock shares outstanding	62,656,102	62,814,368
Treasury Shares Held	16,481,656	16,323,390
Allowances for Loan and Lease Losses, Real Estate	$ 12	$ 11