Fair Value Measurements (Changes in Level 3 Instruments) (Details) - Fair Value, Inputs, Level 3 - USD ($)
$ in Millions |
3 Months Ended |
9 Months Ended |
Sep. 30, 2015 |
Sep. 30, 2014 |
Sep. 30, 2015 |
Sep. 30, 2014 |
| Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |
|
|
|
|
| Changes in Level 3, beginning balance |
|
|
$ 2,594
|
|
| Changes in Level 3, ending balance |
$ 2,689
|
|
2,689
|
|
| Fair Value, Measurements, Recurring |
|
|
|
|
| Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |
|
|
|
|
| Changes in Level 3, beginning balance |
3,855
|
$ 4,130
|
3,948
|
$ 3,878
|
| Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings |
4
|
8
|
7
|
46
|
| Net realized/unrealized gains (losses) included in accumulated other comprehensive income |
9
|
9
|
(65)
|
216
|
| Purchases |
75
|
103
|
254
|
453
|
| Sales |
(28)
|
(56)
|
(171)
|
(284)
|
| Settlements |
(44)
|
(124)
|
(118)
|
(215)
|
| Transfers into Level 3 |
41
|
41
|
83
|
181
|
| Transfers out of Level 3 |
(69)
|
(48)
|
(95)
|
(212)
|
| Changes in Level 3, ending balance |
3,842
|
4,063
|
3,842
|
4,063
|
| Net change in unrealized gains (losses) relating to instruments still held |
0
|
2
|
0
|
12
|
| Fair Value, Measurements, Recurring | Derivatives Assets And Liabilities [Member] |
|
|
|
|
| Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |
|
|
|
|
| Changes in Level 3, beginning balance |
71
|
22
|
28
|
19
|
| Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings |
1
|
3
|
0
|
7
|
| Net realized/unrealized gains (losses) included in accumulated other comprehensive income |
0
|
1
|
3
|
1
|
| Purchases |
1
|
(1)
|
0
|
(1)
|
| Sales |
0
|
0
|
0
|
0
|
| Settlements |
0
|
(1)
|
0
|
(1)
|
| Transfers into Level 3 |
0
|
0
|
42
|
(1)
|
| Transfers out of Level 3 |
0
|
0
|
0
|
0
|
| Changes in Level 3, ending balance |
72
|
24
|
72
|
24
|
| Net change in unrealized gains (losses) relating to instruments still held |
0
|
2
|
0
|
12
|
| Cash Accruals Not Included In Schedule Assets Measured For Fair Value On Recurring Basis |
12
|
9
|
12
|
9
|
| Fair Value, Measurements, Recurring | Retained Interest [Member] |
|
|
|
|
| Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |
|
|
|
|
| Changes in Level 3, beginning balance |
|
1
|
|
1
|
| Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings |
|
0
|
|
0
|
| Net realized/unrealized gains (losses) included in accumulated other comprehensive income |
|
0
|
|
0
|
| Purchases |
|
0
|
|
0
|
| Sales |
|
0
|
|
0
|
| Settlements |
|
(1)
|
|
(1)
|
| Transfers into Level 3 |
|
0
|
|
0
|
| Transfers out of Level 3 |
|
0
|
|
0
|
| Changes in Level 3, ending balance |
|
0
|
|
0
|
| Net change in unrealized gains (losses) relating to instruments still held |
|
0
|
|
0
|
| Fair Value, Measurements, Recurring | Other Assets And Liabilities [Member] |
|
|
|
|
| Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |
|
|
|
|
| Changes in Level 3, beginning balance |
|
0
|
|
0
|
| Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings |
|
0
|
|
0
|
| Net realized/unrealized gains (losses) included in accumulated other comprehensive income |
|
0
|
|
0
|
| Purchases |
|
0
|
|
0
|
| Sales |
|
0
|
|
0
|
| Settlements |
|
0
|
|
0
|
| Transfers into Level 3 |
|
0
|
|
0
|
| Transfers out of Level 3 |
|
0
|
|
0
|
| Changes in Level 3, ending balance |
|
0
|
|
0
|
| Net change in unrealized gains (losses) relating to instruments still held |
0
|
0
|
|
0
|
| Fair Value, Measurements, Recurring | Domestic Corporate Debt Securities [Member] |
|
|
|
|
| Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |
|
|
|
|
| Changes in Level 3, beginning balance |
3,019
|
3,032
|
3,044
|
2,751
|
| Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings |
5
|
4
|
16
|
22
|
| Net realized/unrealized gains (losses) included in accumulated other comprehensive income |
(7)
|
(1)
|
(93)
|
126
|
| Purchases |
74
|
102
|
248
|
440
|
| Sales |
(28)
|
(56)
|
(83)
|
(212)
|
| Settlements |
(37)
|
(90)
|
(93)
|
(158)
|
| Transfers into Level 3 |
35
|
32
|
35
|
170
|
| Transfers out of Level 3 |
(14)
|
0
|
(27)
|
(116)
|
| Changes in Level 3, ending balance |
3,046
|
3,023
|
3,046
|
3,023
|
| Net change in unrealized gains (losses) relating to instruments still held |
0
|
0
|
0
|
0
|
| Fair Value, Measurements, Recurring | US States and Political Subdivisions Debt Securities [Member] |
|
|
|
|
| Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |
|
|
|
|
| Changes in Level 3, beginning balance |
101
|
110
|
115
|
96
|
| Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings |
0
|
0
|
0
|
0
|
| Net realized/unrealized gains (losses) included in accumulated other comprehensive income |
1
|
2
|
(3)
|
9
|
| Purchases |
0
|
2
|
0
|
12
|
| Sales |
0
|
0
|
0
|
0
|
| Settlements |
(5)
|
(1)
|
(15)
|
(4)
|
| Transfers into Level 3 |
0
|
0
|
0
|
0
|
| Transfers out of Level 3 |
(17)
|
0
|
(17)
|
0
|
| Changes in Level 3, ending balance |
81
|
113
|
81
|
113
|
| Net change in unrealized gains (losses) relating to instruments still held |
0
|
0
|
0
|
0
|
| Fair Value, Measurements, Recurring | Residential Mortgage Backed Securities [Member] |
|
|
|
|
| Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |
|
|
|
|
| Changes in Level 3, beginning balance |
2
|
66
|
16
|
86
|
| Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings |
0
|
0
|
5
|
1
|
| Net realized/unrealized gains (losses) included in accumulated other comprehensive income |
0
|
0
|
(4)
|
0
|
| Purchases |
0
|
0
|
0
|
0
|
| Sales |
0
|
0
|
(15)
|
(16)
|
| Settlements |
(1)
|
(3)
|
(1)
|
(8)
|
| Transfers into Level 3 |
0
|
0
|
0
|
0
|
| Transfers out of Level 3 |
0
|
(47)
|
0
|
(47)
|
| Changes in Level 3, ending balance |
2
|
16
|
2
|
16
|
| Net change in unrealized gains (losses) relating to instruments still held |
0
|
0
|
0
|
0
|
| Fair Value, Measurements, Recurring | Commercial Mortgage Backed Securities [Member] |
|
|
|
|
| Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |
|
|
|
|
| Changes in Level 3, beginning balance |
2
|
11
|
9
|
10
|
| Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings |
0
|
0
|
0
|
0
|
| Net realized/unrealized gains (losses) included in accumulated other comprehensive income |
0
|
0
|
0
|
0
|
| Purchases |
0
|
0
|
0
|
0
|
| Sales |
0
|
0
|
(7)
|
0
|
| Settlements |
0
|
(1)
|
0
|
(2)
|
| Transfers into Level 3 |
0
|
0
|
0
|
2
|
| Transfers out of Level 3 |
0
|
0
|
0
|
0
|
| Changes in Level 3, ending balance |
1
|
10
|
1
|
10
|
| Net change in unrealized gains (losses) relating to instruments still held |
0
|
0
|
0
|
0
|
| Fair Value, Measurements, Recurring | Asset-backed Securities [Member] |
|
|
|
|
| Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |
|
|
|
|
| Changes in Level 3, beginning balance |
76
|
130
|
123
|
145
|
| Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings |
(2)
|
1
|
(16)
|
3
|
| Net realized/unrealized gains (losses) included in accumulated other comprehensive income |
0
|
2
|
(5)
|
6
|
| Purchases |
0
|
0
|
0
|
0
|
| Sales |
0
|
0
|
(12)
|
0
|
| Settlements |
0
|
(4)
|
(3)
|
(15)
|
| Transfers into Level 3 |
0
|
0
|
0
|
0
|
| Transfers out of Level 3 |
(36)
|
0
|
(49)
|
(10)
|
| Changes in Level 3, ending balance |
38
|
129
|
38
|
129
|
| Net change in unrealized gains (losses) relating to instruments still held |
0
|
0
|
0
|
0
|
| Fair Value, Measurements, Recurring | Foreign Corporate Debt Securities [Member] |
|
|
|
|
| Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |
|
|
|
|
| Changes in Level 3, beginning balance |
283
|
499
|
336
|
503
|
| Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings |
0
|
0
|
0
|
13
|
| Net realized/unrealized gains (losses) included in accumulated other comprehensive income |
0
|
(1)
|
(4)
|
42
|
| Purchases |
0
|
0
|
0
|
0
|
| Sales |
0
|
0
|
(49)
|
(54)
|
| Settlements |
(1)
|
(23)
|
(1)
|
(24)
|
| Transfers into Level 3 |
0
|
0
|
0
|
1
|
| Transfers out of Level 3 |
0
|
0
|
0
|
(6)
|
| Changes in Level 3, ending balance |
282
|
475
|
282
|
475
|
| Net change in unrealized gains (losses) relating to instruments still held |
0
|
0
|
0
|
0
|
| Fair Value, Measurements, Recurring | Foreign Government Debt Securities [Member] |
|
|
|
|
| Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |
|
|
|
|
| Changes in Level 3, beginning balance |
2
|
1
|
2
|
31
|
| Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings |
0
|
0
|
0
|
0
|
| Net realized/unrealized gains (losses) included in accumulated other comprehensive income |
0
|
0
|
0
|
0
|
| Purchases |
0
|
0
|
0
|
0
|
| Sales |
0
|
0
|
0
|
0
|
| Settlements |
0
|
0
|
0
|
0
|
| Transfers into Level 3 |
0
|
0
|
0
|
0
|
| Transfers out of Level 3 |
(2)
|
(1)
|
(2)
|
(31)
|
| Changes in Level 3, ending balance |
0
|
0
|
0
|
0
|
| Net change in unrealized gains (losses) relating to instruments still held |
0
|
0
|
0
|
0
|
| Fair Value, Measurements, Recurring | US Treasury and Government [Member] |
|
|
|
|
| Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |
|
|
|
|
| Changes in Level 3, beginning balance |
293
|
249
|
266
|
225
|
| Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings |
0
|
0
|
0
|
0
|
| Net realized/unrealized gains (losses) included in accumulated other comprehensive income |
16
|
6
|
44
|
32
|
| Purchases |
0
|
0
|
0
|
0
|
| Sales |
0
|
0
|
0
|
0
|
| Settlements |
0
|
0
|
(1)
|
0
|
| Transfers into Level 3 |
0
|
9
|
0
|
9
|
| Transfers out of Level 3 |
0
|
0
|
0
|
(2)
|
| Changes in Level 3, ending balance |
309
|
264
|
309
|
264
|
| Net change in unrealized gains (losses) relating to instruments still held |
0
|
0
|
0
|
0
|
| Fair Value, Measurements, Recurring | Available-for-sale Securities [Member] |
|
|
|
|
| Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |
|
|
|
|
| Changes in Level 3, beginning balance |
6
|
9
|
9
|
11
|
| Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings |
0
|
0
|
2
|
0
|
| Net realized/unrealized gains (losses) included in accumulated other comprehensive income |
(1)
|
0
|
(3)
|
0
|
| Purchases |
0
|
0
|
6
|
2
|
| Sales |
0
|
0
|
(5)
|
(2)
|
| Settlements |
0
|
0
|
(4)
|
(2)
|
| Transfers into Level 3 |
6
|
0
|
6
|
0
|
| Transfers out of Level 3 |
0
|
0
|
0
|
0
|
| Changes in Level 3, ending balance |
10
|
9
|
10
|
9
|
| Net change in unrealized gains (losses) relating to instruments still held |
$ 0
|
$ 0
|
$ 0
|
$ 0
|