Pension Benefit Plan Accounting Methodology Changes Cash Flows (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net income (loss)	$ 100	$ 88	$ 250	$ 241
Deferred Income Tax Expense (Benefit)			(8)	27
Employee severance and pension			(152)	(587)
Previous Accounting Guidance [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net income (loss)	79		155
Deferred Income Tax Expense (Benefit)			(43)
Employee severance and pension			(22)
Scenario, Actual [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net income (loss)	100		250
Deferred Income Tax Expense (Benefit)			(8)
Employee severance and pension			(152)
Scenario, Previously Reported [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net income (loss)		58		168
Deferred Income Tax Expense (Benefit)				2
Employee severance and pension				(489)
Scenario, Adjusted [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net income (loss)		88		241
Deferred Income Tax Expense (Benefit)				27
Employee severance and pension				$ (587)