Long-Term Debt - Long Term Debt Table (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Debt Instrument [Line Items]
Unamortized discount	$ (26)	$ (33)
HSBC acquisition purchase accounting fair value adjustments	20	22
Long-term debt	9,510	16,427
Secured Debt [Member] | 5.00%-5.99% Fixed Rate Senior Debt [Member]
Debt Instrument [Line Items]
Long-term debt, gross	0	16
Other Fixed Rate Senior Debt [Member] | 2.00%-2.99% Other Fixed Rate Senior Debt [Member]
Debt Instrument [Line Items]
Long-term debt, gross	0	62
Other Fixed Rate Senior Debt [Member] | 3.00%-3.99% Other Fixed Rate Senior Debt Due 2016 [Member]
Debt Instrument [Line Items]
Long-term debt, gross	88	379
Other Fixed Rate Senior Debt [Member] | 4.00%-4.99% Other Fixed Rate Senior Debt Due 2016-2018 [Member]
Debt Instrument [Line Items]
Long-term debt, gross	71	1,855
Other Fixed Rate Senior Debt [Member] | 5.00%-5.49% Other Fixed Rate Senior Debt Due 2016-2021 [Member]
Debt Instrument [Line Items]
Long-term debt, gross	1,289	4,246
Other Fixed Rate Senior Debt [Member] | 5.50%-5.99% Other Fixed Rate Senior Debt Due 2016-2018 [Member]
Debt Instrument [Line Items]
Long-term debt, gross	2,002	2,083
Other Fixed Rate Senior Debt [Member] | 6.00%-6.49% Other Fixed Rate Senior Debt Due 2016-2017 [Member]
Debt Instrument [Line Items]
Long-term debt, gross	1,369	1,463
Other Fixed Rate Senior Debt [Member] | 7.00%-7.49% Other Fixed Rate Senior Debt Due 2023-2032 [Member]
Debt Instrument [Line Items]
Long-term debt, gross	44	46
Other Fixed Rate Senior Debt [Member] | 7.50%-7.99 Other Fixed Rate Senior Debt Due 2019-2032 [Member]
Debt Instrument [Line Items]
Long-term debt, gross	266	276
Variable Interest Rate Debt [Member] | Secured financings – .59% to 2.90%; due 2016 to 2018 [Member]
Debt Instrument [Line Items]
Long-term debt, gross	879	1,473
Variable Interest Rate Debt [Member] | Other variable interest rate senior debt – .84% due 2016 [Member]
Debt Instrument [Line Items]
Long-term debt, gross	1,300	1,300
Subordinated Debt [Member] | Subordinated Debt, 6.68% due 2021 [Member]
Debt Instrument [Line Items]
Long-term debt, gross	2,208	2,208
Junior subordinated notes issued to capital trusts [Member]
Debt Instrument [Line Items]
Long-term debt, gross	$ 0	$ 1,031
Minimum [Member] | Secured Debt [Member] | 5.00%-5.99% Fixed Rate Senior Debt [Member]
Debt Instrument [Line Items]
Stated percentage	5.00%
Minimum [Member] | Other Fixed Rate Senior Debt [Member] | 2.00%-2.99% Other Fixed Rate Senior Debt [Member]
Debt Instrument [Line Items]
Stated percentage	2.00%
Minimum [Member] | Other Fixed Rate Senior Debt [Member] | 3.00%-3.99% Other Fixed Rate Senior Debt Due 2016 [Member]
Debt Instrument [Line Items]
Stated percentage	3.00%
Minimum [Member] | Other Fixed Rate Senior Debt [Member] | 4.00%-4.99% Other Fixed Rate Senior Debt Due 2016-2018 [Member]
Debt Instrument [Line Items]
Stated percentage	4.00%
Minimum [Member] | Other Fixed Rate Senior Debt [Member] | 5.00%-5.49% Other Fixed Rate Senior Debt Due 2016-2021 [Member]
Debt Instrument [Line Items]
Stated percentage	5.00%
Minimum [Member] | Other Fixed Rate Senior Debt [Member] | 5.50%-5.99% Other Fixed Rate Senior Debt Due 2016-2018 [Member]
Debt Instrument [Line Items]
Stated percentage	5.50%
Minimum [Member] | Other Fixed Rate Senior Debt [Member] | 6.00%-6.49% Other Fixed Rate Senior Debt Due 2016-2017 [Member]
Debt Instrument [Line Items]
Stated percentage	6.00%
Minimum [Member] | Other Fixed Rate Senior Debt [Member] | 7.00%-7.49% Other Fixed Rate Senior Debt Due 2023-2032 [Member]
Debt Instrument [Line Items]
Stated percentage	7.00%
Minimum [Member] | Other Fixed Rate Senior Debt [Member] | 7.50%-7.99 Other Fixed Rate Senior Debt Due 2019-2032 [Member]
Debt Instrument [Line Items]
Stated percentage	7.50%
Minimum [Member] | Variable Interest Rate Debt [Member] | Secured financings – .59% to 2.90%; due 2016 to 2018 [Member]
Debt Instrument [Line Items]
Stated percentage	0.59%
Minimum [Member] | Variable Interest Rate Debt [Member] | Other variable interest rate senior debt – .84% due 2016 [Member]
Debt Instrument [Line Items]
Stated percentage	0.00%
Maximum [Member] | Secured Debt [Member] | 5.00%-5.99% Fixed Rate Senior Debt [Member]
Debt Instrument [Line Items]
Stated percentage	5.99%
Maximum [Member] | Other Fixed Rate Senior Debt [Member] | 2.00%-2.99% Other Fixed Rate Senior Debt [Member]
Debt Instrument [Line Items]
Stated percentage	2.99%
Maximum [Member] | Other Fixed Rate Senior Debt [Member] | 3.00%-3.99% Other Fixed Rate Senior Debt Due 2016 [Member]
Debt Instrument [Line Items]
Stated percentage	3.99%
Maximum [Member] | Other Fixed Rate Senior Debt [Member] | 4.00%-4.99% Other Fixed Rate Senior Debt Due 2016-2018 [Member]
Debt Instrument [Line Items]
Stated percentage	4.99%
Maximum [Member] | Other Fixed Rate Senior Debt [Member] | 5.00%-5.49% Other Fixed Rate Senior Debt Due 2016-2021 [Member]
Debt Instrument [Line Items]
Stated percentage	5.49%
Maximum [Member] | Other Fixed Rate Senior Debt [Member] | 5.50%-5.99% Other Fixed Rate Senior Debt Due 2016-2018 [Member]
Debt Instrument [Line Items]
Stated percentage	5.99%
Maximum [Member] | Other Fixed Rate Senior Debt [Member] | 6.00%-6.49% Other Fixed Rate Senior Debt Due 2016-2017 [Member]
Debt Instrument [Line Items]
Stated percentage	6.49%
Maximum [Member] | Other Fixed Rate Senior Debt [Member] | 7.00%-7.49% Other Fixed Rate Senior Debt Due 2023-2032 [Member]
Debt Instrument [Line Items]
Stated percentage	7.49%
Maximum [Member] | Other Fixed Rate Senior Debt [Member] | 7.50%-7.99 Other Fixed Rate Senior Debt Due 2019-2032 [Member]
Debt Instrument [Line Items]
Stated percentage	7.99%
Maximum [Member] | Variable Interest Rate Debt [Member] | Secured financings – .59% to 2.90%; due 2016 to 2018 [Member]
Debt Instrument [Line Items]
Stated percentage	2.90%
Maximum [Member] | Variable Interest Rate Debt [Member] | Other variable interest rate senior debt – .84% due 2016 [Member]
Debt Instrument [Line Items]
Stated percentage		0.84%