Reclassifications out of Accumulated Other Comprehensive Loss Changes in Accumulated Other Comprehensive Loss by Component (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period	$ (4,560)
Other comprehensive income (loss) before reclassifications	384
Amounts reclassified from AOCL	229
Balance at end of period	(3,947)
Foreign Currency Translation Adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period	(538)
Other comprehensive income (loss) before reclassifications	(153)
Amounts reclassified from AOCL	1
Balance at end of period	(690)
Unrecognized Net Actuarial Losses and Prior Service Costs
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period	(4,044)
Other comprehensive income (loss) before reclassifications	528
Amounts reclassified from AOCL	226
Balance at end of period	(3,290)
Deferred Derivative Gains (Losses)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period	(4)
Other comprehensive income (loss) before reclassifications	1
Amounts reclassified from AOCL	2
Balance at end of period	(1)
Unrealized Investment Gains
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period	26
Other comprehensive income (loss) before reclassifications	8
Amounts reclassified from AOCL	0
Balance at end of period	$ 34