Investments (Additional Information) (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended				1 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012 Investments In Other Operating Joint Ventures [Member]	Apr. 30, 2011 Pittsburgh Glass Works LLC	Dec. 31, 2013 Pittsburgh Glass Works LLC	Dec. 31, 2012 Pittsburgh Glass Works LLC	Jul. 31, 2012 Asian Paints Ltd.	Dec. 31, 2012 R S Cogen L L C [Member]
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Percentage Of Ownership Interests				50.00%					50.00%
Equity Method Investment, Ownership Percentage							40.00%
Investments in and Advances to Affiliates, Balance, Principal Amount						$ 30	$ 33
Proceeds from Collection of Advance to Affiliate					168
Repayment of Notes Receivable from Related Parties	0	0	90		90
Proceeds From Return Of Capital From Interest In Affiliates	0	0	78		78
Investments in Joint Venture, Fair Value of Tangible Assets Including Goodwill								22
Investments in Joint Venture, Fair Value of Intangible Assets								12
Noncontrolling Interest in Joint Ventures								49
Equity In Undistributed Earnings Losses Of Subsidiaries	98	79
Proceeds from Dividends Received	$ 9	$ 12	$ 19