Condensed Combined Debtors' Financial Information (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Condensed Combined Debtors' Financial Information [Line Items]
Cash and Cash Equivalents, Disposal Group, Including Discontinued Operations, Period Increase (Decrease)									$ (2)	$ (77)	$ (48)
Disposal Group, Including Discontinued Operation, Cash and Cash Equivalents	0				2				0	2	79	127
Operating cash flows from continuing operations									233	(467)	660
Operating cash flows from discontinued operations, net									(2)	(46)	(34)
Income Statement:
Operating revenues	324	385	315	307	280	340	324	343	1,331	1,287	1,653
Operating expenses									(1,910)	(1,615)	(2,351)
Other income (expense)									5	0	15
Reorganization items, net									(120)	(43)	0
Benefit for income taxes									93	(160)	441
Income (loss) from discontinued operations, net of tax	(15)	(1)	18	(1)	17	(76)	(29)	(24)	1	(112)	(632)
Net Income (Loss)	(27)	(448)	(84)	(82)	(561)	(162)	(104)	(82)	(641)	(909)	(1,079)
Other comprehensive income (loss), net of tax
Other comprehensive loss, net of tax									77	(44)	(63)
Comprehensive Loss									(593)	(969)	(1,141)
Assets:
Total current assets	1,535				1,323				1,535	1,323
Investments in Unconsolidated Affiliates	513				534				513	534
Property, Plant and Equipment, less accumulated depreciation	3,877				4,516				3,877	4,516
Total other assets	103				128				103	128
Total Assets	6,973				7,520				6,973	7,520
Property, Plant and Equipment, accumulated depreciation (in dollars)	1,314				1,431				1,314	1,431
Liabilities and Shareholders' Equity:
Total current liabilities	529				820				529	820
Liabilities subject to compromise	4,015				3,959				4,015	3,959
Deferred taxes	58				81				58	81
Other long-term liabilities	377				528				377	528
Total Liabilities	6,712				6,788				6,712	6,788
Total equity	261				732				261	732	1,664	2,821
Total Liabilities and Equity	6,973				7,520				6,973	7,520
Net Cash (used in) provided by:
Investing cash flows from continuing operations									231	(513)	626
Investing cash flows from discontinued operations, net									112	564	277
Investing cash flows from continuing operations									(57)	(430)	(664)
Investing cash flows from discontinued operations, net									0	(31)	(14)
Net cash provided by (used in) investing activities									(57)	(461)	(678)
Net decrease in cash and cash equivalents									288	(333)	273
Cash and cash equivalents at beginning of period from continuing operations				888				1,221	888	1,221	948
Cash and cash equivalents at end of period from continuing operations	1,176				888				1,176	888	1,221
Debtor Entities
Condensed Combined Debtors' Financial Information [Line Items]
Cash and Cash Equivalents, Disposal Group, Including Discontinued Operations, Period Increase (Decrease)									(2)	(77)
Disposal Group, Including Discontinued Operation, Cash and Cash Equivalents	0				2				0	2	79
Operating cash flows from continuing operations									(3)	(598)
Operating cash flows from discontinued operations, net									(2)	(46)
Income Statement:
Operating revenues									826	901
Operating expenses									(1,517)	(1,262)
Other income (expense)									45	(226)
Reorganization items, net									(120)	(43)
Benefit for income taxes									(41)	(153)
Income (loss) from discontinued operations, net of tax									4	0
Net loss attributable to debtor entities									(803)	(783)
Equity in loss of non-debtor entities, net of tax									133	(142)
Net Income (Loss)									(670)	(925)
Other comprehensive income (loss), net of tax
Comprehensive Loss									(593)	(969)
Assets:
Total current assets	838				638				838	638
Investments in Unconsolidated Affiliates	146				152				146	152
Property, Plant and Equipment, less accumulated depreciation	898				1,428				898	1,428
Investment in non-debtor entities	2,042				2,019				2,042	2,019
Total other assets	873				974				873	974
Total Assets	4,797				5,211				4,797	5,211
Property, Plant and Equipment, accumulated depreciation (in dollars)	555				845				555	845
Liabilities and Shareholders' Equity:
Total current liabilities	250				94				250	94
Liabilities subject to compromise	4,014				3,959				4,014	3,959
Deferred taxes	117				131				117	131
Other long-term liabilities	155				295				155	295
Total Liabilities	4,536				4,479				4,536	4,479
Total equity	261				732				261	732
Total Liabilities and Equity	4,797				5,211				4,797	5,211
Net Cash (used in) provided by:
Investing cash flows from continuing operations									(5)	(644)
Investing cash flows from discontinued operations, net									223	173
Investing cash flows from continuing operations									40	(109)
Investing cash flows from discontinued operations, net									0	(31)
Net cash provided by (used in) investing activities									40	(140)
Net decrease in cash and cash equivalents									260	(534)
Cash and cash equivalents at beginning of period from continuing operations				425				959	425	959
Cash and cash equivalents at end of period from continuing operations	685				425				685	425
Cash paid for reorganization items									$ 72	$ 20