Investment Securities (Available-for-sale and Held-to-maturity Securities, Unrealized Losses) (Details)
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3 Months Ended |
6 Months Ended |
12 Months Ended |
|
Jun. 30, 2016
USD ($)
security
|
Sep. 30, 2015
USD ($)
|
Jun. 30, 2015
USD ($)
|
Jun. 30, 2016
USD ($)
security
|
Jun. 30, 2015
USD ($)
|
Dec. 31, 2015
USD ($)
security
|
Dec. 31, 2014
USD ($)
security
|
Dec. 31, 2013
USD ($)
security
|
| Schedule of Available-for-sale Securities [Line Items] |
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|
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| Purchase of available-for-sale securities |
|
|
|
$ 68,000,000
|
$ 724,000,000
|
$ 1,148,000,000
|
$ 1,278,000,000
|
$ 1,057,000,000
|
| Proceeds from sale of available for sale securities including loans that have been securitized |
|
|
|
5,943,000,000
|
4,558,000,000
|
9,098,000,000
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9,191,000,000
|
3,412,000,000
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| Non-cash reclassification of investment securities AFS to HTM |
|
$ 1,100,000,000
|
|
|
|
1,112,000,000
|
0
|
0
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| Premium on transfer of securities from available-for-sale to held-to-maturity |
|
8,000,000
|
|
|
|
8,000,000
|
|
|
| Unrecognized holding gain on held-to-maturity securities |
|
5,000,000
|
|
|
|
5,000,000
|
|
|
| Purchase of investment securities held-to-maturity |
$ 0
|
|
$ 0
|
15,000,000
|
0
|
217,000,000
|
0
|
0
|
| Investment securities pledged as collateral (less than for the $1 million) |
234,000,000
|
|
|
234,000,000
|
|
14,000,000
|
1,000,000
|
8,000,000
|
| Available-for-sale Securities, Gross Realized Gains (Losses), Sale Proceeds |
1,000,000
|
|
|
1,000,000
|
|
|
|
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| Held-to-maturity Securities, Transferred Security, Unrealized Gain (Loss) |
|
$ 0
|
|
|
|
|
|
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| Available-for-sale Securities, Sold at Par |
175,000,000
|
|
0
|
175,000,000
|
0
|
|
|
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| US Government-sponsored Enterprises Debt Securities |
|
|
|
|
|
|
|
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| Schedule of Available-for-sale Securities [Line Items] |
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|
|
|
|
|
|
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| Purchase of available-for-sale securities |
40,000,000
|
|
$ 72,000,000
|
68,000,000
|
$ 724,000,000
|
1,100,000,000
|
1,200,000,000
|
1,100,000,000
|
| Proceeds from sale of available for sale securities including loans that have been securitized |
|
|
|
|
|
170,000,000
|
414,000,000
|
39,000,000
|
| Gross realized gain (loss) |
|
|
|
|
|
3,000,000
|
4,000,000
|
1,000,000
|
| Municipal obligations |
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|
|
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| Schedule of Available-for-sale Securities [Line Items] |
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|
|
|
|
|
|
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| Purchase of available-for-sale securities |
|
|
|
|
|
14,000,000
|
|
20,000,000
|
| Agency - Commercial |
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|
|
|
|
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| Schedule of Available-for-sale Securities [Line Items] |
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| Available-for-sale Securities, Unrealized Loss Position with Duration 12 Months and Over, Fair Value |
$ 7,000,000
|
|
|
$ 7,000,000
|
|
$ 0
|
$ 53,000,000
|
$ 0
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| Available-for-sale Securities, Unrealized Loss Position with Duration 12 Months and Over, Number of Securities | security |
1
|
|
|
1
|
|
0
|
6
|
0
|
| Available-for-sale Securities, Unrealized Loss Position with Duration 12 Months and Over, Unrealized Loss |
$ 0
|
|
|
$ 0
|
|
$ 0
|
$ 0
|
$ 0
|
| Available-for-sale Securities, Unrealized Loss Position with Duration Under 12 Months, Fair Value |
$ 13,000,000
|
|
|
$ 13,000,000
|
|
$ 482,000,000
|
$ 305,000,000
|
$ 326,000,000
|
| Available-for-sale Securities, Unrealized Loss Position with Duration Under 12 Months, Number of Securities | security |
2
|
|
|
2
|
|
27
|
21
|
19
|
| Available-for-sale Securities, Unrealized Loss Position with Duration Under 12 Months, Unrealized Loss |
$ 0
|
|
|
$ 0
|
|
$ (3,000,000)
|
$ (2,000,000)
|
$ (4,000,000)
|
| Agency - Residential |
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|
|
|
|
|
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| Schedule of Available-for-sale Securities [Line Items] |
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| Available-for-sale Securities, Unrealized Loss Position with Duration 12 Months and Over, Fair Value |
|
|
|
|
|
$ 8,000,000
|
$ 98,000,000
|
$ 0
|
| Available-for-sale Securities, Unrealized Loss Position with Duration 12 Months and Over, Number of Securities | security |
|
|
|
|
|
2
|
10
|
0
|
| Available-for-sale Securities, Unrealized Loss Position with Duration 12 Months and Over, Unrealized Loss |
|
|
|
|
|
$ 0
|
$ (1,000,000)
|
$ 0
|
| Available-for-sale Securities, Unrealized Loss Position with Duration Under 12 Months, Fair Value |
|
|
|
|
|
$ 224,000,000
|
$ 37,000,000
|
$ 500,000,000
|
| Available-for-sale Securities, Unrealized Loss Position with Duration Under 12 Months, Number of Securities | security |
|
|
|
|
|
15
|
4
|
44
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| Available-for-sale Securities, Unrealized Loss Position with Duration Under 12 Months, Unrealized Loss |
|
|
|
|
|
$ (2,000,000)
|
$ 0
|
$ (6,000,000)
|
| Agency - Commercial |
|
|
|
|
|
|
|
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| Schedule of Available-for-sale Securities [Line Items] |
|
|
|
|
|
|
|
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| Held-to-maturity Securities, Unrealized Loss Position with Duration 12 Months and Over, Fair Value |
$ 0
|
|
|
$ 0
|
|
$ 0
|
|
|
| Held-to-maturity Securities, Unrealized Loss Position with Duration 12 Months and Over, Number of Securities | security |
0
|
|
|
0
|
|
0
|
|
|
| Held-to-maturity Securities, Unrealized Loss Position with Duration 12 Months and Over, Unrealized Loss |
$ 0
|
|
|
$ 0
|
|
$ 0
|
|
|
| Held-to-maturity Securities, Unrealized Loss Position with Duration Under 12 Months, Fair Value |
$ 57,000,000
|
|
|
$ 57,000,000
|
|
$ 471,000,000
|
|
|
| Held-to-maturity Securities, Unrealized Loss Position with Duration Under 12 Months, Number of Securities | security |
4
|
|
|
4
|
|
27
|
|
|
| Held-to-maturity Securities, Unrealized Loss Position with Duration Under 12 Months, Unrealized Loss |
$ 0
|
|
|
$ 0
|
|
$ (2,000,000)
|
|
|
| Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss |
$ 0
|
|
|
$ 0
|
|
2,000,000
|
|
|
| Agency - Residential |
|
|
|
|
|
|
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| Schedule of Available-for-sale Securities [Line Items] |
|
|
|
|
|
|
|
|
| Held-to-maturity Securities, Unrealized Loss Position with Duration 12 Months and Over, Fair Value |
|
|
|
|
|
$ 0
|
|
|
| Held-to-maturity Securities, Unrealized Loss Position with Duration 12 Months and Over, Number of Securities | security |
|
|
|
|
|
0
|
|
|
| Held-to-maturity Securities, Unrealized Loss Position with Duration 12 Months and Over, Unrealized Loss |
|
|
|
|
|
$ 0
|
|
|
| Held-to-maturity Securities, Unrealized Loss Position with Duration Under 12 Months, Fair Value |
|
|
|
|
|
$ 547,000,000
|
|
|
| Held-to-maturity Securities, Unrealized Loss Position with Duration Under 12 Months, Number of Securities | security |
|
|
|
|
|
50
|
|
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| Held-to-maturity Securities, Unrealized Loss Position with Duration Under 12 Months, Unrealized Loss |
|
|
|
|
|
$ (4,000,000)
|
|
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| Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss |
|
|
|
|
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$ 4,000,000
|
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|