Stock-Based Compensation - Restricted Stock Activity and Incentive Stock Awards Activity (Detail)	3 Months Ended
	Mar. 31, 2016 $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Outstanding, beginning of period (in dollars per share) | $ / shares	$ 65.89
Granted (in dollars per share) | $ / shares	61.33
Vested (in dollars per share) | $ / shares	50.89
Adjustment for incentive stock awards expected to vest (in dollars per share) | $ / shares	75.66
Canceled (in dollars per share) | $ / shares	69.66
Outstanding, end of period (in dollars per share) | $ / shares	$ 70.90
Restricted Stock and Units
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Outstanding, beginning of period (in shares)	356,885
Granted (in shares)	128,565
Vested (in shares)	(130,083)
Canceled (in shares)	(6,158)
Outstanding, end of period (in shares)	349,209
Incentive Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Outstanding, beginning of period (in shares)	541,638
Granted (in shares)	167,350
Vested (in shares)	(236,951)
Adjustment for incentive stock awards expected to vest (in shares)	(622)
Canceled (in shares)	(3,733)
Outstanding, end of period (in shares)	467,682