Acquisitions (Detail) (USD $) In Millions, unless otherwise specified	1 Months Ended		1 Months Ended
	Apr. 30, 2013 Fianzas Monterrey [Member]	Apr. 02, 2013 Fianzas Monterrey [Member]	May 31, 2013 ABA Seguros [Member]	May 02, 2013 ABA Seguros [Member]	Apr. 28, 2014 The Siam Commercial Samaggi Insurance PCL [Member] Subsequent Event [Member]	Jan. 12, 2014 The Siam Commercial Samaggi Insurance PCL [Member] Subsequent Event [Member]
Business Acquisition [Line Items]
Acquisition purchase price	$ 293		$ 690
Business Acquisition, Percentage of Voting Interests Acquired						60.90%
Business Combination, Step Acquisition, Equity Interest in Acquiree, Percentage						39.10%
Business Acquisition, Purchase Price Allocation, Goodwill Amount		137		285
Business Acquisition, Purchase Price Allocation, Intangible Assets Other than Goodwill		73		140
Business Acquisition, Cost of Acquired Entity, Expected Cash Consideration					$ 190