Condensed Parent Company Statements of Comprehensive Income (Loss) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Expenses									$ 1,819	$ 2,294	$ 1,175
Operating Income (Loss)	(41)	25	5	7	(576)	(147)	(146)	19	(4)	(850)	103
Interest expense, net									356	316	196
(Loss) Before Reorganization Items, Gains on Early Extinguishment of Debt and Provision (Benefit) for Income Taxes									(360)	(1,166)	(93)
Gains on early extinguishment of debt		2			9				2	9	140
Income (Loss) Before Provision (Benefit) for Income Taxes									(358)	(1,195)	47
Provision (benefit) for income taxes									13	(376)	6
Net Income (Loss)	(145)	(59)	(85)	(82)	(556)	(135)	(69)	(59)	(371)	(819)	41
Other comprehensive income (loss)									(51)	10	(16)
Comprehensive Income (Loss)	(205)	(54)	(83)	(80)	(536)	(139)	(76)	(58)	(422)	(809)	25
Parent Company
Expenses									24	22	13
Partnership and equity (income) loss									329	800	(47)
Operating Income (Loss)									(353)	(822)	34
Interest expense, net									34	32	34
(Loss) Before Reorganization Items, Gains on Early Extinguishment of Debt and Provision (Benefit) for Income Taxes									(387)	(854)	0
Gains on early extinguishment of debt									0	0	71
Income (Loss) Before Provision (Benefit) for Income Taxes									(387)	(854)	71
Provision (benefit) for income taxes									(16)	(35)	30
Net Income (Loss)									(371)	(819)	41
Other comprehensive income (loss)									(51)	10	(16)
Comprehensive Income (Loss)									$ (422)	$ (809)	$ 25