INVESTMENT SECURITIES - Investment Securities Classified as Current and Long-Term (Details) - USD ($)
$ in Millions |
Dec. 31, 2019 |
Dec. 31, 2018 |
| Amortized Cost to Fair Value |
|
|
| Amortized Cost |
$ 11,160
|
$ 10,641
|
| Gross Unrealized Gains |
219
|
9
|
| Gross Unrealized Losses |
(8)
|
(213)
|
| Fair Value |
11,371
|
10,437
|
| U.S. Treasury and agency obligations |
|
|
| Amortized Cost to Fair Value |
|
|
| Amortized Cost |
353
|
419
|
| Gross Unrealized Gains |
1
|
1
|
| Gross Unrealized Losses |
0
|
(3)
|
| Fair Value |
354
|
417
|
| Mortgage-backed securities |
|
|
| Amortized Cost to Fair Value |
|
|
| Amortized Cost |
3,628
|
2,595
|
| Gross Unrealized Gains |
85
|
3
|
| Gross Unrealized Losses |
(3)
|
(54)
|
| Fair Value |
3,710
|
2,544
|
| Tax-exempt municipal securities |
|
|
| Amortized Cost to Fair Value |
|
|
| Amortized Cost |
1,433
|
2,805
|
| Gross Unrealized Gains |
30
|
3
|
| Gross Unrealized Losses |
0
|
(37)
|
| Fair Value |
1,463
|
2,771
|
| Residential mortgage-backed securities |
|
|
| Amortized Cost to Fair Value |
|
|
| Amortized Cost |
|
55
|
| Gross Unrealized Gains |
|
0
|
| Gross Unrealized Losses |
|
0
|
| Fair Value |
|
55
|
| Commercial mortgage-backed securities |
|
|
| Amortized Cost to Fair Value |
|
|
| Amortized Cost |
786
|
537
|
| Gross Unrealized Gains |
18
|
0
|
| Gross Unrealized Losses |
0
|
(14)
|
| Fair Value |
804
|
523
|
| Asset-backed securities |
|
|
| Amortized Cost to Fair Value |
|
|
| Amortized Cost |
1,093
|
991
|
| Gross Unrealized Gains |
3
|
1
|
| Gross Unrealized Losses |
(3)
|
(7)
|
| Fair Value |
1,093
|
985
|
| Corporate debt securities |
|
|
| Amortized Cost to Fair Value |
|
|
| Amortized Cost |
3,867
|
3,239
|
| Gross Unrealized Gains |
82
|
1
|
| Gross Unrealized Losses |
(2)
|
(98)
|
| Fair Value |
$ 3,947
|
$ 3,142
|