Stock-based Compensation Plans - Summary of Stock Option Activity (Detail) - $ / shares shares in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Outstanding at beginning of year, Shares	46,502	41,087	38,583
Granted, Shares	5,024	7,672	7,118
Exercised, Shares	(1,156)	(3,357)	(2,561)
Forfeited, Shares	(3,160)	(1,988)	(2,053)
Outstanding at year-end, Shares	47,210	46,502	41,087
Outstanding at beginning of year, Weighted-Average Exercise Price	$ 78.31	$ 78.73	$ 76.10
Granted, Weighted-Average Exercise Price	86.55	76.14	86.86
Exercised, Weighted-Average Exercise Price	57.87	60.70	60.10
Forfeited, Weighted-Average Exercise Price	86.99	84.60	80.34
Outstanding at year-end, Weighted-Average Exercise Price	$ 79.13	$ 78.31	$ 78.73
Cameron
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Assumed in transaction, Shares		3,088
Assumed in transaction, Weighted-Average Exercise Price		$ 63.24