Stock-based Compensation - Additional Information Regarding Options Outstanding (Detail)	12 Months Ended
	Dec. 31, 2016 $ / shares shares
Standard stock options | $2.70 - $3.72
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, lower range limit	$ 2.70
Exercise price range, upper range limit	$ 3.72
Number Outstanding (in shares) | shares	9,438
Weighted Average Remaining Contractual Life (Years)	2 years 2 months 15 days
Weighted Average Exercise Price (in dollars per share)	$ 2.80
Number Exercisable (in shares) | shares	9,438
Weighted Average Exercise Price (in dollars per share)	$ 2.80
Standard stock options | 3.85 - 3.85
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, lower range limit	3.85
Exercise price range, upper range limit	$ 3.85
Number Outstanding (in shares) | shares	600,000
Weighted Average Remaining Contractual Life (Years)	2 years 10 months 13 days
Weighted Average Exercise Price (in dollars per share)	$ 3.85
Number Exercisable (in shares) | shares	600,000
Weighted Average Exercise Price (in dollars per share)	$ 3.85
Standard stock options | 4.95 - 6.61
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, lower range limit	4.95
Exercise price range, upper range limit	$ 6.61
Number Outstanding (in shares) | shares	355,048
Weighted Average Remaining Contractual Life (Years)	4 years 10 months 27 days
Weighted Average Exercise Price (in dollars per share)	$ 6.27
Number Exercisable (in shares) | shares	190,479
Weighted Average Exercise Price (in dollars per share)	$ 6.08
Standard stock options | 6.86 - 8.09
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, lower range limit	6.86
Exercise price range, upper range limit	$ 8.09
Number Outstanding (in shares) | shares	460,593
Weighted Average Remaining Contractual Life (Years)	6 years
Weighted Average Exercise Price (in dollars per share)	$ 7.79
Number Exercisable (in shares) | shares	87,802
Weighted Average Exercise Price (in dollars per share)	$ 7.91
Standard stock options | 8.10 - 9.00
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, lower range limit	8.10
Exercise price range, upper range limit	$ 9.00
Number Outstanding (in shares) | shares	371,903
Weighted Average Remaining Contractual Life (Years)	4 years 6 months 18 days
Weighted Average Exercise Price (in dollars per share)	$ 8.75
Number Exercisable (in shares) | shares	131,372
Weighted Average Exercise Price (in dollars per share)	$ 8.47
Standard stock options | 9.01 - 9.20
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, lower range limit	9.01
Exercise price range, upper range limit	$ 9.2
Number Outstanding (in shares) | shares	271,861
Weighted Average Remaining Contractual Life (Years)	3 years 10 months 27 days
Weighted Average Exercise Price (in dollars per share)	$ 9.18
Number Exercisable (in shares) | shares	178,480
Weighted Average Exercise Price (in dollars per share)	$ 9.17
Standard stock options | 9.53 - 9.53
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, lower range limit	9.53
Exercise price range, upper range limit	$ 9.53
Number Outstanding (in shares) | shares	770,000
Weighted Average Remaining Contractual Life (Years)	3 years 2 months 4 days
Weighted Average Exercise Price (in dollars per share)	$ 9.53
Number Exercisable (in shares) | shares	519,374
Weighted Average Exercise Price (in dollars per share)	$ 9.53
Standard stock options | 9.61 - 12.48
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, lower range limit	9.61
Exercise price range, upper range limit	$ 12.48
Number Outstanding (in shares) | shares	376,478
Weighted Average Remaining Contractual Life (Years)	5 years 3 days
Weighted Average Exercise Price (in dollars per share)	$ 11.89
Number Exercisable (in shares) | shares	220,735
Weighted Average Exercise Price (in dollars per share)	$ 11.95
Standard stock options | 12.49 - 15.12
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, lower range limit	12.49
Exercise price range, upper range limit	$ 15.12
Number Outstanding (in shares) | shares	105,800
Weighted Average Remaining Contractual Life (Years)	2 years 18 days
Weighted Average Exercise Price (in dollars per share)	$ 14.22
Number Exercisable (in shares) | shares	93,588
Weighted Average Exercise Price (in dollars per share)	$ 14.37
Standard stock options | 16.57 - 16.57
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, lower range limit	16.57
Exercise price range, upper range limit	$ 16.57
Number Outstanding (in shares) | shares	100,000
Weighted Average Remaining Contractual Life (Years)	8 months 26 days
Weighted Average Exercise Price (in dollars per share)	$ 16.57
Number Exercisable (in shares) | shares	100,000
Weighted Average Exercise Price (in dollars per share)	$ 16.57
Standard stock options | $2.70 - $16.57
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, lower range limit	2.70
Exercise price range, upper range limit	$ 16.57
Number Outstanding (in shares) | shares	3,421,121
Weighted Average Remaining Contractual Life (Years)	3 years 11 months 26 days
Weighted Average Exercise Price (in dollars per share)	$ 8.44
Number Exercisable (in shares) | shares	2,131,268
Weighted Average Exercise Price (in dollars per share)	$ 8.22
Standard stock options | $8.09 - $8.09
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, lower range limit	8.09
Exercise price range, upper range limit	8.09
Standard stock options | 9.00 - 9.00
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, lower range limit	9.00
Exercise price range, upper range limit	$ 9.00
Market condition based stock options | $8.09 - $8.09
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number Outstanding (in shares) | shares	150,000
Weighted Average Remaining Contractual Life (Years)	5 years 2 months 1 day
Weighted Average Exercise Price (in dollars per share)	$ 8.09
Number Exercisable (in shares) | shares	65,625
Weighted Average Exercise Price (in dollars per share)	$ 8.09
Market condition based stock options | 9.00 - 9.00
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number Outstanding (in shares) | shares	75,000
Weighted Average Remaining Contractual Life (Years)	6 years 1 month 27 days
Weighted Average Exercise Price (in dollars per share)	$ 9.00
Number Exercisable (in shares) | shares	0
Weighted Average Exercise Price (in dollars per share)	$ 0.00
Market condition based stock options | $8.09 - $9.00
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, lower range limit	8.09
Exercise price range, upper range limit	$ 9.00
Number Outstanding (in shares) | shares	225,000
Weighted Average Remaining Contractual Life (Years)	5 years 6 months
Weighted Average Exercise Price (in dollars per share)	$ 8.39
Number Exercisable (in shares) | shares	65,625
Weighted Average Exercise Price (in dollars per share)	$ 8.09