Annual report pursuant to Section 13 and 15(d)

Stockholders' Equity - Narrative (Details)

v3.8.0.1
Stockholders' Equity - Narrative (Details)
 3 Months Ended 9 Months Ended 12 Months Ended
Jan. 24, 2017
USD ($)
shares
Apr. 08, 2016
USD ($)
shares
Oct. 30, 2015
USD ($)
shares
Aug. 04, 2015
USD ($)
shares
Aug. 03, 2015
USD ($)
May 13, 2015
USD ($)
shares
May 04, 2015
USD ($)
Feb. 11, 2015
shares
Jan. 22, 2015
USD ($)
shares
Jan. 20, 2015
shares
Mar. 31, 2017
class
Mar. 31, 2016
USD ($)
Sep. 30, 2017
$ / shares
Dec. 31, 2017
USD ($)
$ / shares
shares
Dec. 31, 2016
USD ($)
$ / shares
shares
Dec. 31, 2015
USD ($)
$ / shares
shares
Apr. 07, 2016
shares
Jan. 12, 2016
USD ($)
Jul. 28, 2015
USD ($)
Dec. 31, 2014
$ / shares
shares
Aug. 13, 2012
shares
Class of Stock [Line Items]                                          
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Number of Shares                               0       23,984  
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested, Number of Shares                               23,984          
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested, Weighted Average Grant Date Fair Value | $ / shares                               $ 1.37          
Number of classes of stock | class                     2                    
Preferred stock, shares authorized                           5,000,000 5,000,000            
Preferred stock, par value (in dollars per share) | $ / shares                           $ 0.001 $ 0.001            
Common stock, shares authorized                           50,000,000 50,000,000            
Common stock, par value (in dollars per share) | $ / shares                           $ 0.001 $ 0.001            
Authorized amount of shares to be repurchased | $             $ 5,000,000.0                     $ 70,000,000.0 $ 15,000,000.0    
Treasury stock, purchase price | $     $ 3,600,000   $ 3,500,000   $ 3,500,000                            
Repurchase of common stock (in shares)     106,264 162,442   186,519                 903,031            
Repurchase of common stock | $     $ 5,000,000.0 $ 5,000,000.0   $ 5,000,000.0                 $ 23,704,000 $ 16,071,000          
Remaining authorized repurchase amount | $                           $ 32,000,000.0              
Number of shares authorized to be repurchased                                         100,000
Allocated Share-based Compensation Expense | $                           $ 35,000 $ 104,000 $ 86,000          
Share-based Compensation Arrangement by Share-based Payment Award Accelerated Compensation Cost | $                       $ 64,000                  
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant                           2,393,873              
Stock Issued During Period, Value, Restricted Stock Award, Gross | $ $ 1,400,000 $ 1,700,000                                      
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Weighted Average Grant Date Fair Value | $ / shares                               $ 0       $ 1.37  
George K. Broady                                          
Class of Stock [Line Items]                                          
Repurchase of common stock (in shares)                 91,817                        
Repurchase of common stock | $                 $ 1,100,000                        
Shares repurchased per trading day                 5,000                        
Restricted Stock [Member]                                          
Class of Stock [Line Items]                                          
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number                           0 22,348 44,712       0  
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value | $ / shares                           $ 12.15 $ 12.15 $ 0          
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value | $ / shares                             $ 12.15            
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period 56,260 51,015           6,116   60,960           67,076          
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period                           (21,930) (22,364) (22,364)          
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value | $ / shares                         $ 12.15 $ 12.15 $ 12.15            
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period                           (418)              
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value | $ / shares                           $ 12.28              
Equity Incentive 2016 Plan [Member] | Restricted Stock [Member]                                          
Class of Stock [Line Items]                                          
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number                           58,032 38,256 0          
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value | $ / shares                           $ 28.72 $ 34.13 $ 0          
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value | $ / shares                           $ 25.44 $ 34.13            
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period                           56,260 51,015            
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period                           (35,336) (12,759)            
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value | $ / shares                           $ 29.58 $ 34.13            
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period                           (1,148)              
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value | $ / shares                           $ 28.55              
Common Stock | Equity Incentive 2016 Plan [Member]                                          
Class of Stock [Line Items]                                          
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized                                 2,500,000