Stock-Based Compensation - Additional Information (Detail) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	$ 1,021,000	$ 976,000	$ 1,926,000	$ 2,154,000
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock vesting period			12 months
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock vesting period			48 months
Common stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee stock purchase plan (ESPP), shares			18,594
2005 Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available for future grants	1,800,000		1,800,000
Stock options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted			100,000
Restricted stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted			1,500,000
Value of restricted stock granted			2,600,000
Stock-based compensation	100,000	100,000	200,000	200,000
Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of market value			85.00%
Percentage of employee's payroll deductions limited to employee's compensation			10.00%
Maximum Stock value of shares purchased by employees if one thousand shares purchased			$ 25,000
Maximum number of shares that employee purchase per period			1,000
Maximum number of shares available for issuance under plan	1,000,000		1,000,000
Shares purchased/granted at a fair value			$ 0.65
Employee Stock Purchase Plan [Member] | September 30, 2013 Offering Period End [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares purchased/granted at a fair value			$ 0.44