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, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Shares		8,400,183	7,897,451	7,620,958	7,436,238
Options Outstanding, Weighted Average Exercise Price Per Share		$ 80.50	$ 57.29	$ 43.63	$ 36.31
Options Outstanding, Weighted Average Remaining Contractual Life (in Years)		3 years
Number, Options Exercisable		1,671,216
Weighted Average Exercise Price, Options Exercisable		$ 52.19
Expected to Vest Options , Shares	[1]	4,949,903
Expected to Vest Options, Weighted Average Exercise Price Per Share		$ 88.86
Range One
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range, Low		36.95
Range, High		$ 46.97
Options Outstanding, Shares		1,298,145
Options Outstanding, Weighted Average Exercise Price Per Share		$ 37.13
Options Outstanding, Weighted Average Remaining Contractual Life (in Years)		1 year
Number, Options Exercisable		717,517
Weighted Average Exercise Price, Options Exercisable		$ 37.25
Expected to Vest Options , Shares	[1]	574,626
Expected to Vest Options, Weighted Average Exercise Price Per Share		$ 36.97
Range Two
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range, Low		53.38
Range, High		$ 73.65
Options Outstanding, Shares		1,805,950
Options Outstanding, Weighted Average Exercise Price Per Share		$ 53.49
Options Outstanding, Weighted Average Remaining Contractual Life (in Years)		2 years
Number, Options Exercisable		571,450
Weighted Average Exercise Price, Options Exercisable		$ 53.45
Expected to Vest Options , Shares	[1]	1,098,889
Expected to Vest Options, Weighted Average Exercise Price Per Share		$ 53.50
Range Three
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		2,321,238
Options Outstanding, Weighted Average Exercise Price Per Share		$ 78.31
Options Outstanding, Weighted Average Remaining Contractual Life (in Years)		3 years 2 months 12 days
Number, Options Exercisable		380,249
Weighted Average Exercise Price, Options Exercisable		$ 78.25
Expected to Vest Options , Shares	[1]	1,295,612
Expected to Vest Options, Weighted Average Exercise Price Per Share		$ 78.34
Range Four
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range, Low		102.21
Range, High		$ 142.43
Options Outstanding, Shares		2,974,850
Options Outstanding, Weighted Average Exercise Price Per Share		$ 117.54
Options Outstanding, Weighted Average Remaining Contractual Life (in Years)		4 years 2 months 12 days
Number, Options Exercisable		2,000
Weighted Average Exercise Price, Options Exercisable		$ 102.21
Expected to Vest Options , Shares	[1]	1,980,776
Expected to Vest Options, Weighted Average Exercise Price Per Share		$ 117.52

[1] Assumes a weighted average forfeiture rate of 9.95%.