Stock Based Compensation - Schedule of Stock Options Exercise Price (Detail) shares in Thousands	12 Months Ended
	Dec. 31, 2015 $ / shares shares
Class of Stock [Line Items]
Exercise Price, Options Outstanding	5,003
Exercise Price, Options Exercisable	2,545
Exercise Price Range 1 [Member]
Class of Stock [Line Items]
Exercise Price, Minimum | $ / shares	$ 10.00
Exercise Price, Maximum | $ / shares	$ 27.83
Exercise Price, Options Outstanding	1,938
Exercise Price, Weighted Average Remaining Vesting Life in Years	26 days
Exercise Price, Options Exercisable	1,713
Exercise Price Range 2 [Member]
Class of Stock [Line Items]
Exercise Price, Minimum | $ / shares	$ 29.99
Exercise Price, Maximum | $ / shares	$ 40.65
Exercise Price, Options Outstanding	995
Exercise Price, Weighted Average Remaining Vesting Life in Years	6 months
Exercise Price, Options Exercisable	712
Exercise Price Range 3 [Member]
Class of Stock [Line Items]
Exercise Price, Minimum | $ / shares	$ 47.63
Exercise Price, Maximum | $ / shares	$ 58.02
Exercise Price, Options Outstanding	5
Exercise Price, Weighted Average Remaining Vesting Life in Years	1 year 26 days
Exercise Price Range 4 [Member]
Class of Stock [Line Items]
Exercise Price, Minimum | $ / shares	$ 74.99
Exercise Price, Maximum | $ / shares	$ 111.09
Exercise Price, Options Outstanding	231
Exercise Price, Weighted Average Remaining Vesting Life in Years	1 year 8 months 19 days
Exercise Price, Options Exercisable	55
Exercise Price Range 5 [Member]
Class of Stock [Line Items]
Exercise Price, Minimum | $ / shares	$ 115.45
Exercise Price, Maximum | $ / shares	$ 138.47
Exercise Price, Options Outstanding	347
Exercise Price, Weighted Average Remaining Vesting Life in Years	2 years 6 months 7 days
Exercise Price, Options Exercisable	63
Exercise Price Range 6 [Member]
Class of Stock [Line Items]
Exercise Price, Minimum | $ / shares	$ 146.36
Exercise Price, Maximum | $ / shares	$ 158.24
Exercise Price, Options Outstanding	1,487
Exercise Price, Weighted Average Remaining Vesting Life in Years	2 years 5 months 9 days
Exercise Price, Options Exercisable	2