Long-Term Debt (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Debt Instrument [Line Items]
Total long-term debt	$ 3,560	$ 3,111
2016 Notes - 3.500% Notes due 2016
Debt Instrument [Line Items]
Senior Long Term Notes	500	500
2017 Notes - 2.300% Notes due 2017
Debt Instrument [Line Items]
Senior Long Term Notes	500	500
2019 Notes - 8.125% Notes due 2019
Debt Instrument [Line Items]
Senior Long Term Notes	810	861
2020 Notes - 6.875% Notes due 2020
Debt Instrument [Line Items]
Senior Long Term Notes	750	750
2023 Notes - 3.750% Notes due 2023
Debt Instrument [Line Items]
Senior Long Term Notes	500
2040 Notes - 8.125% Notes due 2040
Debt Instrument [Line Items]
Senior Long Term Notes	250	250
2041 Notes - 7.000% Notes due 2041
Debt Instrument [Line Items]
Senior Long Term Notes	$ 250	$ 250