Subsequent Events (Detail) - USD ($)	1 Months Ended	3 Months Ended
	Apr. 30, 2016	Mar. 31, 2016	Mar. 31, 2015
Subsequent Event [Line Items]
Stock repurchase programs, authorized amount		$ 7,000,000,000
Common stock dividends per share declared (in dollars per share)		$ 0.10	$ 0.10
Subsequent Event [Member]
Subsequent Event [Line Items]
Stock repurchase programs, authorized amount	$ 2,000,000,000
Common stock dividends per share declared (in dollars per share)	$ 0.10