Goodwill and Intangible Assets (Details) (USD $)
In Thousands, unless otherwise specified
 3 Months Ended 12 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Dec. 31, 2014
Goodwill, Gross      
Balance, beginning of period $ 64,858    
Foreign currency fluctuations (3,492)    
Balance, end of period 61,366    
Accumulated Impairment Losses      
Balance, beginning of period (46,503)    
Foreign currency fluctuations 2,694    
Balance, end of period (43,809)    
Goodwill, Net      
Balance, beginning of period 18,355    
Foreign currency fluctuations (798)    
Balance, end of period 17,557    
Acquired Finite-lived Intangible Assets      
Original cost 30,698   33,161
Accumulated amortization (16,477)   (17,573)
Intangible Assets, Net 14,221   15,588
Amortization expense 520 611  
Estimated aggregate amortization expense of Intangible Assets      
Remaining 2015 1,390    
2016 1,639    
2017 1,542    
2018 1,536    
2019 1,428    
Thereafter 6,686    
Total 14,221    
Customer Lists      
Acquired Finite-lived Intangible Assets      
Original cost 20,324   21,946
Accumulated amortization (11,356)   (12,099)
Intangible Assets, Net 8,968   9,847
Weighted-average original life 15 years   15 years
Trade Name      
Acquired Finite-lived Intangible Assets      
Original cost 3,812   4,300
Accumulated amortization (1,903)   (2,068)
Intangible Assets, Net 1,909   2,232
Weighted-average original life 14 years   14 years
Technology      
Acquired Finite-lived Intangible Assets      
Original cost 6,562   6,915
Accumulated amortization (3,218)   (3,406)
Intangible Assets, Net $ 3,344   $ 3,509
Weighted-average original life 13 years   13 years