Schedule of Weighted Average Remaining Contractual Life for Options Outstanding and Weighted Average Exercise Price Per Share for Exercisable Options (Detail) - $ / shares		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Shares		9,674,791	9,639,949	8,770,133	8,400,183
Options Outstanding, Weighted Average Exercise Price Per Share		$ 115.39	$ 112.40	$ 99.06	$ 80.50
Options Outstanding, Weighted Average Remaining Contractual Life (in Years)		2 years 7 months 6 days
Number, Options Exercisable		3,724,179
Weighted Average Exercise Price, Options Exercisable		$ 106.77
Expected to Vest Options , Shares	[1]	4,414,324
Expected to Vest Options, Weighted Average Exercise Price Per Share		$ 120.82
Range One
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range, Low		78.17
Range, High		$ 96.98
Options Outstanding, Shares		1,134,475
Options Outstanding, Weighted Average Exercise Price Per Share		$ 78.17
Options Outstanding, Weighted Average Remaining Contractual Life (in Years)		2 months 12 days
Number, Options Exercisable		1,134,475
Weighted Average Exercise Price, Options Exercisable		$ 78.17
Expected to Vest Options, Weighted Average Exercise Price Per Share		78.17
Range Two
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range, Low		102.21
Range, High		$ 118.60
Options Outstanding, Shares		1,788,801
Options Outstanding, Weighted Average Exercise Price Per Share		$ 117.14
Options Outstanding, Weighted Average Remaining Contractual Life (in Years)		1 year 3 months 18 days
Number, Options Exercisable		1,183,150
Weighted Average Exercise Price, Options Exercisable		$ 117.25
Expected to Vest Options , Shares	[1]	572,521
Expected to Vest Options, Weighted Average Exercise Price Per Share		$ 117.14
Range Three
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range, Low		118.62
Range, High		$ 124.22
Options Outstanding, Shares		4,288,690
Options Outstanding, Weighted Average Exercise Price Per Share		$ 119.19
Options Outstanding, Weighted Average Remaining Contractual Life (in Years)		3 years 3 months 18 days
Number, Options Exercisable		854,088
Weighted Average Exercise Price, Options Exercisable		$ 118.64
Expected to Vest Options , Shares	[1]	2,265,877
Expected to Vest Options, Weighted Average Exercise Price Per Share		$ 119.19
Range Four
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range, Low		124.44
Range, High		$ 138.00
Options Outstanding, Shares		2,462,825
Options Outstanding, Weighted Average Exercise Price Per Share		$ 124.65
Options Outstanding, Weighted Average Remaining Contractual Life (in Years)		3 years 2 months 12 days
Number, Options Exercisable		552,466
Weighted Average Exercise Price, Options Exercisable		$ 124.68
Expected to Vest Options , Shares	[1]	1,575,926
Expected to Vest Options, Weighted Average Exercise Price Per Share		$ 124.65

[1] Assumes a weighted average forfeiture rate of 13.06%.