| Goodwill by Operating Segment | 
Goodwill by operating segment is as follows (in thousands): 
 
|  |  | Supply Chain Management |  |  | IT, Energy and Management Consulting |  |  | Aviation |  |  | Total |  |  
|  Balance as of December 31, 2015 |  | $ | 63,113 |  |  | $ | 30,883 |  |  | $ | 104,549 |  |  | $ | 198,545 |  |  
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
|  Balance as of March 31, 2016 |  | $ | 63,113 |  |  | $ | 30,883 |  |  | $ | 104,549 |  |  | $ | 198,545 |  |  | 
| Schedule of Intangible Assets | 
Intangible assets were comprised of the following (in thousands): 
 
|  |  | Cost |  |  | Accumulated Amortization |  |  | Accumulated Impairment Loss |  |  | Net Intangible Assets |  |  
| March 31, 2016 |  |  |  |  |  |  |  |  |  |  |  |  |  
| Contract and customer-related |  | $ | 173,084 |  |  | $ | (49,911 | ) |  | $ | (1,025 | ) |  | $ | 122,148 |  |  
| Acquired technologies |  |  | 12,400 |  |  |  | (5,432 | ) |  |  | - |  |  |  | 6,968 |  |  
| Trade names – amortizable |  |  | 16,730 |  |  |  | (6,823 | ) |  |  | - |  |  |  | 9,907 |  |  
|     Total |  | $ | 202,214 |  |  | $ | (62,166 | ) |  | $ | (1,025 | ) |  | $ | 139,023 |  |  
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
| December 31, 2015 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
| Contract and customer-related |  | $ | 173,084 |  |  | $ | (46,611 | ) |  | $ | (1,025 | ) |  | $ | 125,448 |  |  
| Acquired technologies |  |  | 12,400 |  |  |  | (5,151 | ) |  |  | - |  |  |  | 7,249 |  |  
| Trade names |  |  | 16,730 |  |  |  | (6,384 | ) |  |  | - |  |  |  | 10,346 |  |  
|     Total |  | $ | 202,214 |  |  | $ | (58,146 | ) |  | $ | (1,025 | ) |  | $ | 143,043 |  |  |