Consolidated Statement of Comprehensive Income (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Net Income (Loss) Attributable to Parent [Abstract]
Net income (loss)	$ 147	$ (1,184)	$ 539
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax, Including OTTI	7
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax		3	3
Other comprehensive income (loss):
Other Comprehensive Income (Loss), Net of Tax	9	3	2
Unrealized gain (loss) on post-retirement benefits, net of tax	2	0	(1)
Comprehensive income (loss)	$ 156	$ (1,181)	$ 541