Share-Based Compensation - Schedule of Information with Respect to Outstanding and Exercisable Stock Options (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Number of Options Outstanding	2,437,609	2,818,433	2,868,053	3,085,888
Options Outstanding, Weighted Average Exercise Price	$ 9.32	$ 9.59	$ 9.86	$ 11.18
Options Outstanding, Weighted Average Remaining Contractual Term (in Years)	5 years 6 months 3 days
Options Exercisable, Number Exercisable	1,895,851
Options Exercisable, Weighted Average Exercise Price	$ 9.08
Range of Exercise Prices $2.82 - $4.07 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices, Minimum	2.82
Range of Exercise Prices, Maximum	$ 4.07
Options Outstanding, Number of Options Outstanding	280,632
Options Outstanding, Weighted Average Exercise Price	$ 3.71
Options Outstanding, Weighted Average Remaining Contractual Term (in Years)	4 years 8 months 15 days
Options Exercisable, Number Exercisable	280,632
Options Exercisable, Weighted Average Exercise Price	$ 3.71
Range of Exercise Prices $4.15 - $4.15 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices, Minimum	4.15
Range of Exercise Prices, Maximum	$ 4.15
Options Outstanding, Number of Options Outstanding	250,732
Options Outstanding, Weighted Average Exercise Price	$ 4.15
Options Outstanding, Weighted Average Remaining Contractual Term (in Years)	5 years 7 months 9 days
Options Exercisable, Number Exercisable	250,732
Options Exercisable, Weighted Average Exercise Price	$ 4.15
Range of Exercise Prices $4.49 - $4.49 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices, Minimum	4.49
Range of Exercise Prices, Maximum	$ 4.49
Options Outstanding, Number of Options Outstanding	607,648
Options Outstanding, Weighted Average Exercise Price	$ 4.49
Options Outstanding, Weighted Average Remaining Contractual Term (in Years)	6 years 2 months 4 days
Options Exercisable, Number Exercisable	436,872
Options Exercisable, Weighted Average Exercise Price	$ 4.49
Range of Exercise Prices $5.00 - $6.51 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices, Minimum	5.00
Range of Exercise Prices, Maximum	$ 6.51
Options Outstanding, Number of Options Outstanding	302,032
Options Outstanding, Weighted Average Exercise Price	$ 6.02
Options Outstanding, Weighted Average Remaining Contractual Term (in Years)	4 years 4 months 24 days
Options Exercisable, Number Exercisable	302,032
Options Exercisable, Weighted Average Exercise Price	$ 6.02
Range of Exercise Prices $7.22 - $8.30 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices, Minimum	7.22
Range of Exercise Prices, Maximum	$ 8.30
Options Outstanding, Number of Options Outstanding	258,023
Options Outstanding, Weighted Average Exercise Price	$ 8.21
Options Outstanding, Weighted Average Remaining Contractual Term (in Years)	6 years 10 months 13 days
Options Exercisable, Number Exercisable	133,473
Options Exercisable, Weighted Average Exercise Price	$ 8.12
Range of Exercise Prices $9.69 - $13.15 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices, Minimum	9.69
Range of Exercise Prices, Maximum	$ 13.15
Options Outstanding, Number of Options Outstanding	84,065
Options Outstanding, Weighted Average Exercise Price	$ 9.90
Options Outstanding, Weighted Average Remaining Contractual Term (in Years)	6 years 8 months 23 days
Options Exercisable, Number Exercisable	84,065
Options Exercisable, Weighted Average Exercise Price	$ 9.90
Range of Exercise Prices $13.80 - $13.80 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices, Minimum	13.80
Range of Exercise Prices, Maximum	$ 13.80
Options Outstanding, Number of Options Outstanding	266,312
Options Outstanding, Weighted Average Exercise Price	$ 13.80
Options Outstanding, Weighted Average Remaining Contractual Term (in Years)	8 years 2 months 4 days
Options Exercisable, Number Exercisable	61,838
Options Exercisable, Weighted Average Exercise Price	$ 13.80
Range of Exercise Prices $15.39 - $22.13 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices, Minimum	15.39
Range of Exercise Prices, Maximum	$ 22.13
Options Outstanding, Number of Options Outstanding	226,653
Options Outstanding, Weighted Average Exercise Price	$ 20.23
Options Outstanding, Weighted Average Remaining Contractual Term (in Years)	4 years 7 months 9 days
Options Exercisable, Number Exercisable	184,695
Options Exercisable, Weighted Average Exercise Price	$ 20.00
Range of Exercise Prices $29.02 - $29.02 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices, Minimum	29.02
Range of Exercise Prices, Maximum	$ 29.02
Options Outstanding, Number of Options Outstanding	41,512
Options Outstanding, Weighted Average Exercise Price	$ 29.02
Options Outstanding, Weighted Average Remaining Contractual Term (in Years)	2 months 1 day
Options Exercisable, Number Exercisable	41,512
Options Exercisable, Weighted Average Exercise Price	$ 29.02
Range of Exercise Prices $30.67 - $30.67 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices, Minimum	30.67
Range of Exercise Prices, Maximum	$ 30.67
Options Outstanding, Number of Options Outstanding	120,000
Options Outstanding, Weighted Average Exercise Price	$ 30.67
Options Outstanding, Weighted Average Remaining Contractual Term (in Years)	4 months 17 days
Options Exercisable, Number Exercisable	120,000
Options Exercisable, Weighted Average Exercise Price	$ 30.67