INVESTMENT SECURITIES - Schedule of Investment Securities Classified as Current and Long-Term (Detail) - USD ($)
$ in Millions |
Sep. 30, 2016 |
Dec. 31, 2015 |
| Investment [Line Items] |
|
|
| Amortized Cost |
$ 9,246
|
$ 9,018
|
| Gross Unrealized Gains |
381
|
218
|
| Gross Unrealized Losses |
(25)
|
(126)
|
| Fair Value |
9,602
|
9,110
|
| Debt Securities | Tax-exempt municipal securities |
|
|
| Investment [Line Items] |
|
|
| Amortized Cost |
3,157
|
2,611
|
| Gross Unrealized Gains |
73
|
61
|
| Gross Unrealized Losses |
(4)
|
(4)
|
| Fair Value |
3,226
|
2,668
|
| Debt Securities | Residential Mortgage-Backed Securities |
|
|
| Investment [Line Items] |
|
|
| Amortized Cost |
10
|
13
|
| Gross Unrealized Gains |
0
|
0
|
| Gross Unrealized Losses |
0
|
0
|
| Fair Value |
10
|
13
|
| Debt Securities | Commercial Mortgage-Backed Securities |
|
|
| Investment [Line Items] |
|
|
| Amortized Cost |
498
|
1,024
|
| Gross Unrealized Gains |
13
|
2
|
| Gross Unrealized Losses |
(8)
|
(41)
|
| Fair Value |
503
|
985
|
| Debt Securities | Asset-backed securities |
|
|
| Investment [Line Items] |
|
|
| Amortized Cost |
187
|
264
|
| Gross Unrealized Gains |
1
|
1
|
| Gross Unrealized Losses |
0
|
(2)
|
| Fair Value |
188
|
263
|
| Debt Securities | Corporate debt securities |
|
|
| Investment [Line Items] |
|
|
| Amortized Cost |
3,223
|
2,873
|
| Gross Unrealized Gains |
268
|
140
|
| Gross Unrealized Losses |
(12)
|
(55)
|
| Fair Value |
3,479
|
2,958
|
| Debt Securities | U.S. Treasury and other U.S. government corporations and agencies: | U.S. Treasury and agency obligations |
|
|
| Investment [Line Items] |
|
|
| Amortized Cost |
659
|
331
|
| Gross Unrealized Gains |
2
|
2
|
| Gross Unrealized Losses |
0
|
(1)
|
| Fair Value |
661
|
332
|
| Debt Securities | U.S. Treasury and other U.S. government corporations and agencies: | Mortgage-backed securities |
|
|
| Investment [Line Items] |
|
|
| Amortized Cost |
1,512
|
1,902
|
| Gross Unrealized Gains |
24
|
12
|
| Gross Unrealized Losses |
(1)
|
(23)
|
| Fair Value |
$ 1,535
|
$ 1,891
|