Stock-Based Compensation, Dividend Restrictions, and Calculations of Earnings Per Share of Common Stock - Calculations of Earnings Per Share of Common Stock (Detail) (USD $) In Millions, except Per Share data, 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
Income Statement [Abstract]
Net Income from Continuing Operations	$ 58	$ 110	$ 53	$ (111)	$ 34	$ 87	$ 47	$ 50	$ 110	$ 218	$ 222
Net loss from discontinued operations		8	(11)	(319)	9	25	15	18	(322)	67	35
Net (loss) income	$ 58	$ 118	$ 42	$ (430)	$ 43	$ 112	$ 62	$ 68	$ (212)	$ 285	$ 257
Average shares outstanding									246	229	226
Adjustment to shares outstanding
Weighted Average Shares Outstanding for Computation of Basic Earnings Per Share of Common Stock									246	229	226
Net effect of potentially dilutive shares										1
Weighted Average Shares Outstanding for Computation of Diluted Earnings Per Share of Common Stock									246	230	226
Basic earnings per share of common stock from continuing operations					$ 0.15	$ 0.38	$ 0.20	$ 0.22	$ 0.45	$ 0.95	$ 0.98
Basic (loss) earnings per share of common stock from discontinued operations					$ 0.03	$ 0.11	$ 0.07	$ 0.08	$ (1.31)	$ 0.30	$ 0.16
Basic (loss) earnings per share					$ 0.18	$ 0.49	$ 0.27	$ 0.30	$ (0.86)	$ 1.25	$ 1.14
Diluted earnings per share of common stock from continuing operations					$ 0.15	$ 0.38	$ 0.20	$ 0.22	$ 0.45	$ 0.95	$ 0.98
Diluted (loss) earnings per share of common stock from discontinued operations					$ 0.03	$ 0.11	$ 0.07	$ 0.08	$ (1.31)	$ 0.29	$ 0.16
Diluted (loss) earnings per share					$ 0.18	$ 0.49	$ 0.27	$ 0.30	$ (0.86)	$ 1.24	$ 1.14