Accounting for Stock-Based Compensation - Summary of Stock Options Outstanding and Exercisable (Detail) (USD $)	9 Months Ended
	Sep. 30, 2013
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number Outstanding	3,002,480
Weighted Average Remaining Contractual Life	1 year 1 month 6 days
Weighted Average Exercise Price	$ 1.50
Range of Exercise Prices from $1.15 to $1.36 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Minimum Range of Exercise Price	$ 1.15
Maximum Range of Exercise Price	$ 1.36
Number Outstanding	2,287,500
Weighted Average Remaining Contractual Life	8 months 12 days
Weighted Average Exercise Price	$ 1.15
Range of Exercise Prices from $2.00 to $3.00 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Minimum Range of Exercise Price	$ 2.00
Maximum Range of Exercise Price	$ 3.00
Number Outstanding	539,980
Weighted Average Remaining Contractual Life	2 years
Weighted Average Exercise Price	$ 2.33
Range of Exercise Prices from $3.10 to $4.65 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Minimum Range of Exercise Price	$ 3.10
Maximum Range of Exercise Price	$ 4.65
Number Outstanding	155,000
Weighted Average Remaining Contractual Life	4 years 1 month 6 days
Weighted Average Exercise Price	$ 3.17
Range of Exercise Prices from $4.99 to $6.96 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Minimum Range of Exercise Price	$ 4.99
Maximum Range of Exercise Price	$ 6.96
Number Outstanding	20,000
Weighted Average Remaining Contractual Life	7 months 6 days
Weighted Average Exercise Price	$ 5.68