Income Taxes (Details) - USD ($) $ in Millions |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2015 |
Jun. 30, 2014 |
Jun. 30, 2015 |
Jun. 30, 2014 |
|
| Income Tax Disclosure [Abstract] | ||||
| Income tax expense (benefit) | $ 577 | $ (254) | $ 1,106 | $ (478) |
| Tax expense (benefit), entities included in effective tax rate calculation | 793 | 1,300 | ||
| Deferred Tax Assets, Net | $ 33,400 | $ 33,400 | ||