Debt (Details)
$ in Millions |
6 Months Ended |
12 Months Ended |
|
Jun. 30, 2016
USD ($)
subsidiary
|
Dec. 31, 2015
USD ($)
subsidiary
quarter
|
Dec. 31, 2014
USD ($)
|
| Debt Instrument [Line Items] |
|
|
|
| Trust Preferred Securities |
|
$ 247
|
$ 247
|
| Total long-term debt |
$ 247
|
$ 247
|
$ 331
|
| Number of subsidiaries | subsidiary |
9
|
9
|
|
| Trust preferred securities, accrued interest |
$ 31
|
$ 27
|
|
| One Month LIBOR |
|
|
|
| Debt Instrument [Line Items] |
|
|
|
| Interest Rate (percent) |
|
|
0.17%
|
| Debt instrument, variable interest rate term (in months) |
|
|
1 month
|
| Three Month LIBOR |
|
|
|
| Debt Instrument [Line Items] |
|
|
|
| Interest Rate (percent) |
|
0.61%
|
0.26%
|
| Debt instrument, variable interest rate term (in months) |
3 months
|
3 months
|
3 months
|
| 3ML plus 3.25% matures 2032 |
|
|
|
| Debt Instrument [Line Items] |
|
|
|
| Basis spread on variable rate (percent) |
3.25%
|
3.25%
|
|
| Trust Preferred Securities |
$ 26
|
$ 26
|
$ 26
|
| Interest Rate (percent) |
3.89%
|
3.85%
|
3.50%
|
| 3ML plus 3.25% matures 2033 |
|
|
|
| Debt Instrument [Line Items] |
|
|
|
| Basis spread on variable rate (percent) |
3.25%
|
3.25%
|
|
| Trust Preferred Securities |
$ 26
|
$ 26
|
$ 26
|
| Interest Rate (percent) |
3.88%
|
3.57%
|
3.48%
|
| 3ML plus 3.25% matures 2033 |
|
|
|
| Debt Instrument [Line Items] |
|
|
|
| Basis spread on variable rate (percent) |
3.25%
|
3.25%
|
|
| Trust Preferred Securities |
$ 26
|
$ 26
|
$ 26
|
| Interest Rate (percent) |
3.88%
|
3.85%
|
3.51%
|
| 3ML plus 2.00% matures 2035 |
|
|
|
| Debt Instrument [Line Items] |
|
|
|
| Basis spread on variable rate (percent) |
2.00%
|
2.00%
|
|
| Trust Preferred Securities |
$ 26
|
$ 26
|
$ 26
|
| Interest Rate (percent) |
2.63%
|
2.32%
|
2.23%
|
| 3ML plus 2.00% matures 2035 |
|
|
|
| Debt Instrument [Line Items] |
|
|
|
| Basis spread on variable rate (percent) |
2.00%
|
2.00%
|
|
| Trust Preferred Securities |
$ 26
|
$ 26
|
$ 26
|
| Interest Rate (percent) |
2.63%
|
2.32%
|
2.23%
|
| 3ML plus 1.75% matures 2035 |
|
|
|
| Debt Instrument [Line Items] |
|
|
|
| Basis spread on variable rate (percent) |
1.75%
|
1.75%
|
|
| Trust Preferred Securities |
$ 51
|
$ 51
|
$ 51
|
| Interest Rate (percent) |
2.40%
|
2.26%
|
1.99%
|
| 3ML plus 1.50% matures 2035 |
|
|
|
| Debt Instrument [Line Items] |
|
|
|
| Basis spread on variable rate (percent) |
1.50%
|
1.50%
|
|
| Trust Preferred Securities |
$ 25
|
$ 25
|
$ 25
|
| Interest Rate (percent) |
2.13%
|
1.82%
|
1.73%
|
| 3ML plus 1.45% matures 2037 |
|
|
|
| Debt Instrument [Line Items] |
|
|
|
| Basis spread on variable rate (percent) |
1.45%
|
1.45%
|
|
| Trust Preferred Securities |
$ 25
|
$ 25
|
$ 25
|
| Interest Rate (percent) |
2.10%
|
1.96%
|
1.69%
|
| 3ML plus 2.50% matures 2037 |
|
|
|
| Debt Instrument [Line Items] |
|
|
|
| Basis spread on variable rate (percent) |
2.50%
|
2.50%
|
|
| Trust Preferred Securities |
$ 16
|
$ 16
|
$ 16
|
| Interest Rate (percent) |
3.15%
|
3.01%
|
2.74%
|
| 3ML plus 0.46% maturing 2018 |
|
|
|
| Debt Instrument [Line Items] |
|
|
|
| Basis spread on variable rate (percent) |
|
0.46%
|
|
| 3ML plus 0.46% maturing 2018 | One Month LIBOR |
|
|
|
| Debt Instrument [Line Items] |
|
|
|
| Basis spread on variable rate (percent) |
|
0.46%
|
|
| Interest Rate (percent) |
|
16.00%
|
|
| Debt instrument, variable interest rate term (in months) |
|
1 month
|
|
| 3ML plus 0.46% maturing 2018 | HELOC Securitizations |
|
|
|
| Debt Instrument [Line Items] |
|
|
|
| Total long-term debt |
|
$ 0
|
$ 42
|
| Interest Rate (percent) |
|
|
0.63%
|
| Debt Instrument, Face Amount |
|
|
$ 43
|
| 3ML plus 0.16% matures 2019 |
|
|
|
| Debt Instrument [Line Items] |
|
|
|
| Basis spread on variable rate (percent) |
|
0.16%
|
|
| Interest Rate (percent) |
|
16.00%
|
|
| 3ML plus 0.16% matures 2019 | HELOC Securitizations |
|
|
|
| Debt Instrument [Line Items] |
|
|
|
| Total long-term debt |
|
$ 0
|
$ 42
|
| Interest Rate (percent) |
|
|
0.33%
|
| Debt Instrument, Face Amount |
|
|
$ 45
|
| Junior Subordinated Debt [Member] |
|
|
|
| Debt Instrument [Line Items] |
|
|
|
| Maximum period for interest payment deferrals (in quarters) | quarter |
|
20
|
|
| Debt Instrument, Interest Payment Deferment Period | quarter |
|
16
|
|