Noncash Investing and Financing Activities (Detail) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Interest paid
Interest	$ 392	$ 351
Income taxes paid, net
Income taxes	335	384
Transfers:
Portfolio loans to loans held for sale	470	117
Loans held for sale to portfolio loans	274	24
Portfolio loans to OREO	$ 77	117
Loans held for sale to OREO		$ 2