Investments (Contractual Maturities Debt Securities) (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Held-to-maturity, Amortized cost
Total debt securities	$ 11,126	$ 441
Due in one year or less	33
Due after one year through five years	130
Due after five years through 10 years	232
Due after 10 years	$ 10,731
Held-to-maturity, Weighted average yield
Total debt securities	1.90%
Due in one year or less	3.32%
Due after one year through five years	3.13%
Due after five years through 10 years	2.86%
Due after 10 years	1.86%
Available-for-sale, Amortized cost
Available-for-sale	$ 13,538	24,202
Due in one year or less	137
Due after one year through five years	1,386
Due after five years through 10 years	2,725
Due after 10 years	$ 9,290
Available-for-sale, Weighted average yield
Total debt securities	2.13%
Due in one year or less	2.65%
Due after one year through five years	2.48%
Due after five years through 10 years	2.15%
Due after 10 years	2.06%
Total investment securities, Amortized cost
Total debt securities	$ 24,664	24,643
Due in one year or less	170
Due after one year through five years	1,516
Due after five years through 10 years	2,957
Due after 10 years	$ 20,021
Total investment securities, Weighted average yield
Total debt securities	2.16%
Due in one year or less	2.78%
Due after one year through five years	2.54%
Due after five years through 10 years	2.21%
Due after 10 years	2.06%
U.S. Treasury securities
Available-for-sale, Amortized cost
Available-for-sale	$ 557	155
Due in one year or less	0
Due after one year through five years	0
Due after five years through 10 years	0
Due after 10 years	$ 557
Available-for-sale, Weighted average yield
Total debt securities	2.05%
Due in one year or less	0.00%
Due after one year through five years	0.00%
Due after five years through 10 years	0.00%
Due after 10 years	2.05%
Agency securities
Held-to-maturity, Amortized cost
Total debt securities	$ 100
Due in one year or less	0
Due after one year through five years	0
Due after five years through 10 years	0
Due after 10 years	$ 100
Held-to-maturity, Weighted average yield
Total debt securities	3.50%
Due in one year or less	0.00%
Due after one year through five years	0.00%
Due after five years through 10 years	0.00%
Due after 10 years	3.50%
Available-for-sale, Amortized cost
Available-for-sale	$ 782	833
Due in one year or less	0
Due after one year through five years	345
Due after five years through 10 years	230
Due after 10 years	$ 207
Available-for-sale, Weighted average yield
Total debt securities	2.61%
Due in one year or less	0.00%
Due after one year through five years	2.40%
Due after five years through 10 years	2.49%
Due after 10 years	3.10%
Agency guaranteed mortgage-backed securities
Held-to-maturity, Amortized cost
Total debt securities	$ 10,621
Due in one year or less	0
Due after one year through five years	0
Due after five years through 10 years	49
Due after 10 years	$ 10,572
Held-to-maturity, Weighted average yield
Total debt securities	1.84%
Due in one year or less	0.00%
Due after one year through five years	0.00%
Due after five years through 10 years	2.02%
Due after 10 years	1.84%
Available-for-sale, Amortized cost
Available-for-sale	$ 9,652	20,549
Due in one year or less	25
Due after one year through five years	305
Due after five years through 10 years	1,625
Due after 10 years	$ 7,697
Available-for-sale, Weighted average yield
Total debt securities	1.92%
Due in one year or less	4.27%
Due after one year through five years	1.53%
Due after five years through 10 years	2.03%
Due after 10 years	1.91%
Small Business Administration loan-backed securities
Available-for-sale, Amortized cost
Available-for-sale	$ 740	938
Due in one year or less	0
Due after one year through five years	43
Due after five years through 10 years	154
Due after 10 years	$ 543
Available-for-sale, Weighted average yield
Total debt securities	3.83%
Due in one year or less	0.00%
Due after one year through five years	4.22%
Due after five years through 10 years	3.66%
Due after 10 years	3.84%
Municipal securities
Held-to-maturity, Amortized cost
Total debt securities	$ 405	441
Due in one year or less	33
Due after one year through five years	130
Due after five years through 10 years	183
Due after 10 years	$ 59
Held-to-maturity, Weighted average yield
Total debt securities	3.05%
Due in one year or less	3.32%
Due after one year through five years	3.13%
Due after five years through 10 years	3.09%
Due after 10 years	2.61%
Available-for-sale, Amortized cost
Available-for-sale	$ 1,732	1,652
Due in one year or less	112
Due after one year through five years	643
Due after five years through 10 years	706
Due after 10 years	$ 271
Available-for-sale, Weighted average yield
Total debt securities	2.24%
Due in one year or less	2.29%
Due after one year through five years	2.73%
Due after five years through 10 years	1.90%
Due after 10 years	1.94%
Other debt securities
Available-for-sale, Amortized cost
Available-for-sale	$ 75	$ 75
Due in one year or less	0
Due after one year through five years	50
Due after five years through 10 years	10
Due after 10 years	$ 15
Available-for-sale, Weighted average yield
Total debt securities	5.39%
Due in one year or less	0.00%
Due after one year through five years	4.25%
Due after five years through 10 years	9.52%
Due after 10 years	6.44%