Stock-based Compensation - Additional Disclosures (Details) (USD $)
3 Months Ended 9 Months Ended 0 Months Ended 3 Months Ended 9 Months Ended
Sep. 30, 2014
Sep. 30, 2013
Sep. 30, 2014
Sep. 30, 2013
Sep. 30, 2014
Stock Options [Member]
Sep. 30, 2014
Restricted Stock Units (RSUs) [Member]
Sep. 30, 2014
Former Chief Executive Officer [Member]
Sep. 30, 2014
Former Chief Executive Officer [Member]
Stock Options [Member]
Aug. 04, 2014
Employees, Excluding Directors and Officers [Member]
employee
Aug. 04, 2014
Employees, Excluding Directors and Officers [Member]
Stock Options [Member]
Aug. 04, 2014
CEO [Member]
Aug. 04, 2014
Minimum [Member]
Employees, Excluding Directors and Officers [Member]
Sep. 30, 2014
Option Modification [Member]
Employees, Excluding Directors and Officers [Member]
Sep. 30, 2014
Option Modification [Member]
Employees, Excluding Directors and Officers [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                            
Stock-based compensation expense $ 1,226,000 $ 683,000 $ 2,754,000 $ 1,862,000                 $ 300,000 $ 300,000
Tax deduction allowed for incentive stock options     0                      
Deferred income tax asset for the expense related to options 0   0                      
Closing stock price as reported on the NASDAQ $ 1.91   $ 1.91                      
Total intrinsic value of options exercised     500,000                      
Weighted average fair value of options issued (in dollars per share)     $ 1.32                      
Unrecognized compensation cost related to non-vested options granted 6,800,000   6,800,000                      
Unrecognized compensation cost related to RSUs           2,100,000                
Expected weighted-average period to recognize unrecognized compensation cost         2 years 11 months 5 days 2 years 11 months                
Total fair value of shares vested     1,300,000                      
Number of shares modified               752,725   1,547,382        
Contractual term               10 years            
Incremental compensation expense from plan modification             $ 200,000   $ 600,000          
Option modification, minimum exercise price required for modification (in dollars per share)                       $ 3.00    
Number of employees affected by plan modification                 203          
Reset exercise price (in dollars per share)                 $ 2.38          
Number of stock options granted     4,972,895 [1]               2,001,338      
Options granted, exercise price (in dollars per share)     $ 2.56 [1]               $ 2.38      
[1] The number of options granted and forfeited includes options cancelled and replaced in conjunction with the modifications described below.