Stock-Based Compensation - Information about Stock Options Outstanding Under All Stock Plans (Detail) (USD $)	3 Months Ended
	Mar. 31, 2014
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Lower range of exercise prices	$ 5.50
Upper range of exercise prices	$ 11.00
Options Outstanding, Number	1,402,725
Options Outstanding, Weighted Average Contractual Life (Years)	4 years 8 months 9 days
Options Outstanding, Weighted Average Exercise Price	$ 7.79
Options Exercisable, Number	495,374
Options Exercisable, Weighted Average Exercise Price	$ 8.88
Range One [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Lower range of exercise prices	$ 5.50
Upper range of exercise prices	$ 6.86
Options Outstanding, Number	60,209
Options Outstanding, Weighted Average Contractual Life (Years)	4 years 6 months 7 days
Options Outstanding, Weighted Average Exercise Price	$ 6.58
Options Exercisable, Number	41,425
Options Exercisable, Weighted Average Exercise Price	$ 6.65
Range Two [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Lower range of exercise prices	$ 6.87
Upper range of exercise prices	$ 7.93
Options Outstanding, Number	922,306
Options Outstanding, Weighted Average Contractual Life (Years)	5 years 9 months 11 days
Options Outstanding, Weighted Average Exercise Price	$ 7.22
Options Exercisable, Number	47,739
Options Exercisable, Weighted Average Exercise Price	$ 7.66
Range Three [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Lower range of exercise prices	$ 7.94
Upper range of exercise prices	$ 8.63
Options Outstanding, Number	37,645
Options Outstanding, Weighted Average Contractual Life (Years)	2 years 8 months 9 days
Options Outstanding, Weighted Average Exercise Price	$ 8.49
Options Exercisable, Number	32,895
Options Exercisable, Weighted Average Exercise Price	$ 8.49
Range Four [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Lower range of exercise prices	$ 8.64
Upper range of exercise prices	$ 8.76
Options Outstanding, Number	28,500
Options Outstanding, Weighted Average Contractual Life (Years)	2 years 3 months 11 days
Options Outstanding, Weighted Average Exercise Price	$ 8.76
Options Exercisable, Number	26,500
Options Exercisable, Weighted Average Exercise Price	$ 8.76
Range Five [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Lower range of exercise prices	$ 8.77
Upper range of exercise prices	$ 9.09
Options Outstanding, Number	105,250
Options Outstanding, Weighted Average Contractual Life (Years)	1 year 7 months 6 days
Options Outstanding, Weighted Average Exercise Price	$ 9.08
Options Exercisable, Number	100,000
Options Exercisable, Weighted Average Exercise Price	$ 9.09
Range Six [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Lower range of exercise prices	$ 9.10
Upper range of exercise prices	$ 9.12
Options Outstanding, Number	6,575
Options Outstanding, Weighted Average Contractual Life (Years)	2 years 2 months 23 days
Options Outstanding, Weighted Average Exercise Price	$ 9.11
Options Exercisable, Number	6,575
Options Exercisable, Weighted Average Exercise Price	$ 9.11
Range Seven [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Lower range of exercise prices	$ 9.13
Upper range of exercise prices	$ 9.16
Options Outstanding, Number	132,000
Options Outstanding, Weighted Average Contractual Life (Years)	2 years 4 months 2 days
Options Outstanding, Weighted Average Exercise Price	$ 9.16
Options Exercisable, Number	132,000
Options Exercisable, Weighted Average Exercise Price	$ 9.16
Range Eight [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Lower range of exercise prices	$ 9.17
Upper range of exercise prices	$ 10.25
Options Outstanding, Number	69,280
Options Outstanding, Weighted Average Contractual Life (Years)	3 years 2 months 27 days
Options Outstanding, Weighted Average Exercise Price	$ 9.40
Options Exercisable, Number	67,280
Options Exercisable, Weighted Average Exercise Price	$ 9.39
Range Nine [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Lower range of exercise prices	$ 10.26
Upper range of exercise prices	$ 10.50
Options Outstanding, Number	1,400
Options Outstanding, Weighted Average Contractual Life (Years)	4 years 4 months 2 days
Options Outstanding, Weighted Average Exercise Price	$ 10.46
Options Exercisable, Number	1,400
Options Exercisable, Weighted Average Exercise Price	$ 10.46
Range Ten [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Lower range of exercise prices	$ 10.51
Upper range of exercise prices	$ 11.00
Options Outstanding, Number	39,560
Options Outstanding, Weighted Average Contractual Life (Years)	2 years 1 month 21 days
Options Outstanding, Weighted Average Exercise Price	$ 10.65
Options Exercisable, Number	39,560
Options Exercisable, Weighted Average Exercise Price	$ 10.65