Stock-Based Compensation - Additional Information (Detail) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016 USD ($) performance_metric $ / shares shares	Dec. 31, 2015 USD ($) $ / shares shares	Dec. 31, 2014 USD ($) $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for issuance (in shares) | shares	2,400,000
Common stock available for issuance (in shares) | shares	749,178
Weighted-average remaining contractual term, stock options outstanding	1 year 10 months 24 days	2 years 10 months 24 days
Weighted-average remaining contractual term, stock options vested and exercisable	1 year 10 months 24 days
Aggregate intrinsic value, stock options outstanding	$ 0
Aggregate intrinsic value, stock options vested and exercisable	13,800
Stock options vested (in shares) | shares		0
Intrinsic value, stock options exercised	1,300	$ 700	$ 4,200
Cash received from stock option exercises	491	$ 116	$ 753
Restricted stock units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grant-date intrinsic value	$ 14,300
Weighted-average grant-date fair value (in $ per share) | $ / shares	$ 80.33	$ 134.37	$ 183.83
Fair value of awards vested	$ 9,300	$ 11,800	$ 21,100
Share settlement under RSUs (in shares) | shares	19,592	37,488	50,952
Cash used for employee withholding tax payments	$ 1,500	$ 5,100	$ 9,100
Unamortized stock-based compensation expense	$ 16,000	$ 16,700
Weighted average remaining amortization period	1 year 4 months 24 days	1 year 8 months 12 days
Restricted stock units (RSUs), performance-based [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards granted (in shares) | shares	33,244	33,632
Number of performance metrics | performance_metric	2
Stock-based compensation expense	$ 2,800	$ 2,500
Unamortized stock-based compensation expense	$ 3,300	$ 6,200
Compensation expense recognition period	3 years
Stock options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Contractual life in years	10 years
Vesting period of stock options in years	3 years
Unvested stock options (in shares) | shares	0
Minimum [Member] | Restricted stock units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Contractual life in years	1 year
Maximum [Member] | Restricted stock units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Contractual life in years	3 years