Derivative Financial Instruments (Schedule of Changes in Fair Value) (Details) - USD ($)
$ in Millions |
Jun. 30, 2016 |
Dec. 31, 2015 |
Dec. 31, 2014 |
| Other assets |
|
|
|
| Assets |
|
|
|
| Notional Amount |
|
$ 8,970
|
$ 5,844
|
| Fair Value |
|
58
|
46
|
| Other liabilities |
|
|
|
| Liabilities |
|
|
|
| Notional Amount |
$ 14,513
|
4,013
|
3,865
|
| Fair Value |
79
|
14
|
20
|
| Mortgage backed securities forwards |
|
|
|
| Liabilities |
|
|
|
| Fair Value |
|
6
|
|
| Designated as Hedging Instrument | Interest rate swaps on FHLB advances |
|
|
|
| Assets |
|
|
|
| Fair Value |
2
|
|
|
| Liabilities |
|
|
|
| Fair Value |
56
|
4
|
|
| Designated as Hedging Instrument | Interest rate swaps on FHLB advances | Other assets |
|
|
|
| Assets |
|
|
|
| Notional Amount |
250
|
|
|
| Fair Value |
2
|
|
|
| Designated as Hedging Instrument | Interest rate swaps on FHLB advances | Other liabilities |
|
|
|
| Liabilities |
|
|
|
| Notional Amount |
825
|
825
|
|
| Fair Value |
56
|
4
|
|
| Not Designated as Hedging Instrument |
|
|
|
| Assets |
|
|
|
| Fair Value |
95
|
32
|
52
|
| Liabilities |
|
|
|
| Fair Value |
79
|
14
|
|
| Not Designated as Hedging Instrument | Other assets |
|
|
|
| Assets |
|
|
|
| Notional Amount |
9,859
|
8,970
|
|
| Fair Value |
178
|
58
|
|
| Not Designated as Hedging Instrument | U.S. Treasury and euro dollar futures |
|
|
|
| Assets |
|
|
|
| Fair Value |
3
|
|
18
|
| Liabilities |
|
|
|
| Fair Value |
3
|
1
|
|
| Not Designated as Hedging Instrument | U.S. Treasury and euro dollar futures | Other assets |
|
|
|
| Assets |
|
|
|
| Notional Amount |
749
|
1,892
|
2,530
|
| Fair Value |
3
|
0
|
7
|
| Not Designated as Hedging Instrument | U.S. Treasury and euro dollar futures | Other liabilities |
|
|
|
| Liabilities |
|
|
|
| Notional Amount |
7,903
|
768
|
687
|
| Fair Value |
3
|
1
|
1
|
| Not Designated as Hedging Instrument | Mortgage backed securities forwards |
|
|
|
| Assets |
|
|
|
| Fair Value |
4
|
7
|
26
|
| Liabilities |
|
|
|
| Fair Value |
58
|
6
|
|
| Not Designated as Hedging Instrument | Mortgage backed securities forwards | Other assets |
|
|
|
| Assets |
|
|
|
| Notional Amount |
468
|
1,931
|
355
|
| Fair Value |
4
|
7
|
2
|
| Not Designated as Hedging Instrument | Mortgage backed securities forwards | Other liabilities |
|
|
|
| Liabilities |
|
|
|
| Notional Amount |
6,054
|
2,655
|
2,789
|
| Fair Value |
58
|
6
|
13
|
| Not Designated as Hedging Instrument | Rate lock commitments | Other assets |
|
|
|
| Assets |
|
|
|
| Notional Amount |
6,305
|
3,593
|
2,604
|
| Fair Value |
83
|
26
|
31
|
| Not Designated as Hedging Instrument | Rate lock commitments | Other liabilities |
|
|
|
| Liabilities |
|
|
|
| Notional Amount |
46
|
168
|
22
|
| Fair Value |
0
|
0
|
0
|
| Not Designated as Hedging Instrument | Interest rate swaps |
|
|
|
| Assets |
|
|
|
| Fair Value |
|
25
|
8
|
| Liabilities |
|
|
|
| Fair Value |
|
7
|
6
|
| Not Designated as Hedging Instrument | Interest rate swaps | Other assets |
|
|
|
| Assets |
|
|
|
| Notional Amount |
|
1,554
|
355
|
| Fair Value |
|
25
|
6
|
| Not Designated as Hedging Instrument | Interest rate swaps | Other liabilities |
|
|
|
| Liabilities |
|
|
|
| Notional Amount |
510
|
422
|
367
|
| Fair Value |
18
|
7
|
$ 6
|
| Not Designated as Hedging Instrument | Interest Rate Swaps and Swaptions |
|
|
|
| Assets |
|
|
|
| Fair Value |
88
|
25
|
|
| Liabilities |
|
|
|
| Fair Value |
18
|
7
|
|
| Not Designated as Hedging Instrument | Interest Rate Swaps and Swaptions | Other assets |
|
|
|
| Assets |
|
|
|
| Notional Amount |
2,337
|
1,554
|
|
| Fair Value |
$ 88
|
$ 25
|
|