Share-Based Compensation - Activity Related to Stock Options (Detail) - Stock Option Awards - $ / shares	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Number of shares
Balance at beginning of the period (in shares)	721,538,000	813,777,000
Granted (in shares)	71,491,000	149,932,000
Exercised (in shares)	(64,163,000)	(8,811,000)
Forfeited or expired (in shares)	(15,091,000)	(45,723,000)
Balance at end of the period (in shares)	713,775,000	909,175,000
Exercisable at period end (in shares)	470,841,000	598,469,000
Weighted Average Exercise Price
Balance at beginning of the period (in usd per share)	$ 55.38	$ 56.99
Granted (in usd per share)	85.42	47.46
Exercised (in usd per share)	55.05	55.62
Forfeited or expired (in usd per share)	74.72	60.97
Balance at end of the period (in usd per share)	58.01	55.23
Exercisable at period end (in usd per share)	$ 55.79	$ 56.31