Total Other Non-Operating Expense (Details) - USD ($) $ in Millions			3 Months Ended	12 Months Ended
	Oct. 13, 2014	Jul. 02, 2014	Sep. 30, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Schedule of Other Nonoperating Income (Expense) [Line Items]
Other Nonoperating Expense				$ 0	$ 128	$ 129
Entek
Schedule of Other Nonoperating Income (Expense) [Line Items]
Investment In Affiliate Ownership Percentage Sold					49.62%
Equity Method Investment, Purchase Price Agreement	$ 125				$ 125
Equity Method Investment, Other than Temporary Impairment	$ 68		$ 18		86
Other Nonoperating Expense					86	0
Silver Ridge Power
Schedule of Other Nonoperating Income (Expense) [Line Items]
Equity Method Investment, Purchase Price Agreement		$ 179
Equity Method Investment, Other than Temporary Impairment					42
Equity Method Investment, Ownership Percentage Sold		50.00%
Equity Method Investment, Net Sales Proceeds		$ 179
Other Nonoperating Expense					42	0
Elsta
Schedule of Other Nonoperating Income (Expense) [Line Items]
Equity Method Investment, Other than Temporary Impairment						129
Other Nonoperating Expense					$ 0
Equity Method Investments						240
Equity Method Investments, Fair Value Disclosure						$ 111