Segment Information - Schedule of Segment Reporting Information, by Segment (Parenthetical) (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Segment Reporting Information [Line Items]
Interest expense included in the segment results	$ 391	$ 340	$ 298
Interest Income Excluded From Segment Information
Segment Reporting Information [Line Items]
Interest income included in the segment results	11		3
Interest Expense Excluded From Segment Information
Segment Reporting Information [Line Items]
Interest expense included in the segment results	$ 23	$ 8	$ 8