Annual report pursuant to Section 13 and 15(d)

Nature of Business and Significant Accounting Policies - ASC 606 (Details)

v3.10.0.1
Nature of Business and Significant Accounting Policies - ASC 606 (Details) - USD ($)
$ in Thousands
3 Months Ended 12 Months Ended
Dec. 31, 2018
Sep. 30, 2018
Jun. 30, 2018
Mar. 31, 2018
Dec. 31, 2017
Sep. 30, 2017
Jun. 30, 2017
Mar. 31, 2017
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Jan. 01, 2018
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]                        
Receivables, net $ 60,004       $ 55,760       $ 60,004 $ 55,760   $ 56,250
Unbilled receivables, net 41,255       42,577       41,255 42,577   45,961
Inventories, net 166,392       132,591       166,392 132,591   130,834
Accounts payable 57,408       66,015       57,408 66,015   65,517
Accrued expenses and other current liabilities 37,133       40,243       37,133 40,243   40,898
Deferred tax liabilities 18,482       19,423       18,482 19,423   19,918
Retained earnings 301,073       267,902       301,073 267,902   269,367
Revenues 180,996 $ 168,931 $ 170,394 $ 176,897 194,795 $ 174,164 $ 193,860 $ 197,294 697,218 760,113 $ 691,790  
Provision for income taxes                 10,168 5,989 14,881  
Net income 9,243 $ 10,034 $ 8,751 $ 7,052 17,357 $ 6,639 $ 7,807 $ 7,293 35,080 39,096 26,793  
Deferred taxes                 (1,371) (10,534) (1,146)  
Receivables, net                 (3,754) (91) (12,166)  
Unbilled receivables, net                 4,706 2,972 (10,581)  
Inventories, net                 (35,558) 3,749 (27,217)  
Accounts payable and deferred compensation                 (7,405) (23,587) 54,743  
Accrued expenses and other current liabilities                 (2,515) 7,562 4,253  
Net cash provided by operating activities                 18,855 50,420 47,193  
Without Adoption of ASC 606                        
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]                        
Receivables, net         55,760         55,760    
Unbilled receivables, net 36,451       42,577       36,451 42,577    
Inventories, net 169,673       132,591       169,673 132,591    
Accounts payable         66,015         66,015    
Accrued expenses and other current liabilities 37,133       40,243       37,133 40,243    
Deferred tax liabilities 18,097       19,423       18,097 19,423    
Retained earnings $ 299,936       $ 267,902       299,936 267,902    
Provision for income taxes                 10,281      
Net income                 35,406      
Deferred taxes                 (1,260)      
Receivables, net                 (4,244)      
Unbilled receivables, net                 6,126      
Inventories, net                 (37,082)      
Accounts payable and deferred compensation                 (7,903)      
Accrued expenses and other current liabilities                 (1,860)      
Net cash provided by operating activities                 18,855      
ASU 2014-09 | Effect of ASC 606 Increase/(Decrease)                        
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]                        
Receivables, net                       490
Unbilled receivables, net                       3,384
Inventories, net                       (1,757)
Accounts payable                       (498)
Accrued expenses and other current liabilities                       655
Deferred tax liabilities                       495
Retained earnings                       $ 1,465
Products                        
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]                        
Revenues                 360,505 350,129 341,776  
Costs and operating expenses                 303,881 291,769 279,629  
Products | Without Adoption of ASC 606                        
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]                        
Revenues                 358,496      
Costs and operating expenses                 302,356      
Services                        
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]                        
Revenues                 336,713 409,984 350,014  
Costs and operating expenses                 321,076 $ 395,573 $ 337,956  
Services | Without Adoption of ASC 606                        
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]                        
Revenues                 337,635      
Costs and operating expenses                 $ 321,076