Schedule of Pension Plan Assets at Fair Value (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Defined Benefit Plan Disclosure [Line Items]
Money market funds	$ 3	$ 2
Equity funds	26	27
Bond/fixed-income funds	28	25
Real-estate indirect investment	5	4
Commodities/Other	4	3
Insurance contracts	10	8	7
Total Assets at fair value	76	69
Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Money market funds	0	0
Equity funds	0	0
Bond/fixed-income funds	0	0
Real-estate indirect investment	0	0
Commodities/Other	0	0
Insurance contracts	0	0
Total Assets at fair value	0	0
Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Money market funds	3	2
Equity funds	26	27
Bond/fixed-income funds	28	25
Real-estate indirect investment	5	4
Commodities/Other	4	3
Insurance contracts	0	0
Total Assets at fair value	66	61
Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Money market funds	0	0
Equity funds	0	0
Bond/fixed-income funds	0	0
Real-estate indirect investment	0	0
Commodities/Other	0	0
Insurance contracts	10	8
Total Assets at fair value	$ 10	$ 8