Summary of Spin-Off Costs within pre-tax Earnings (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Spin-Off Transaction [Line Items]
Spin-Off costs	$ 62	$ 1,053	$ 46
Selling, general and administrative expenses
Spin-Off Transaction [Line Items]
Spin-Off costs	62	444	46
Interest And Other Expense
Spin-Off Transaction [Line Items]
Spin-Off costs		$ 609