Provision (Benefit) for Income Taxes Deferred Tax Table (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Deferred income tax liabilities:
Property, plant, and equipment	$ 4	$ 4
Investments	5,272	5,472
Other	15	10
Total deferred income tax liabilities	5,291	5,486
Deferred income tax assets:
Accrued liabilities	150	178
Minimum tax credits	139	137
Foreign tax credit	193	251
Federal loss carryovers	485	134
State losses and credits	296	250
Other	42	97
Total deferred income tax assets	1,305	1,047
Less valuation allowance	190	206
Net deferred income tax assets	1,115	841
Overall net deferred income tax liabilities	$ 4,176	$ 4,645