Quarterly report pursuant to Section 13 or 15(d)

Goodwill and Intangible Assets- Additional Information (Details)

v3.8.0.1
Goodwill and Intangible Assets- Additional Information (Details) - USD ($)
$ in Thousands
 3 Months Ended
Mar. 31, 2018
Mar. 31, 2017
Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]      
Gross Carrying Amount $ 26,231   $ 25,998
Accumulated Amortization 24,000   23,558
Intangible assets, net 2,231   2,440
Amortization of intangible assets 253 $ 380  
Customer contracts      
Finite-Lived Intangible Assets [Line Items]      
Gross Carrying Amount 7,836   7,786
Accumulated Amortization 7,836   7,786
Amortization of intangible assets 0 7  
Customer relationships      
Finite-Lived Intangible Assets [Line Items]      
Gross Carrying Amount 12,035   11,863
Accumulated Amortization 9,921   9,557
Non-compete agreements      
Finite-Lived Intangible Assets [Line Items]      
Gross Carrying Amount 3,079   3,052
Accumulated Amortization 3,077   3,048
Technology      
Finite-Lived Intangible Assets [Line Items]      
Gross Carrying Amount 2,737   2,751
Accumulated Amortization 2,641   2,642
Trade names      
Finite-Lived Intangible Assets [Line Items]      
Gross Carrying Amount 544   546
Accumulated Amortization 525   $ 525
Customer Relationships, Noncompete Agreements, Technology and Trade Names      
Finite-Lived Intangible Assets [Line Items]      
Amortization of intangible assets $ 253 $ 373  
Minimum      
Finite-Lived Intangible Assets [Line Items]      
Estimated useful life 1 year    
Minimum | Customer contracts      
Finite-Lived Intangible Assets [Line Items]      
Acquired intangible assets useful life 1 year    
Minimum | Other intangible assets      
Finite-Lived Intangible Assets [Line Items]      
Estimated useful life 4 years    
Maximum      
Finite-Lived Intangible Assets [Line Items]      
Estimated useful life 15 years    
Maximum | Customer contracts      
Finite-Lived Intangible Assets [Line Items]      
Acquired intangible assets useful life 5 years    
Maximum | Other intangible assets      
Finite-Lived Intangible Assets [Line Items]      
Estimated useful life 15 years