Supplementary Data (Details) - USD ($)
$ in Thousands
Jun. 30, 2018
Dec. 31, 2017
Other current assets:    
Other current assets $ 152 $ 97
Total other current assets 2,460 986
Current portion of long-term debt and capital lease obligations:    
Long-term Debt 2,072 16,927
Capital leases 330 324
Total current portion of long-term debt and capital lease obligations 2,402 17,251
Other current liabilities:    
Federal income taxes payable 618 1,120
Deferred rent 257 241
Total other current liabilities 875 1,361
Accrued liabilities:    
Accrued salaries and wages 2,750 2,643
Accrued incentive compensation 4,272 6,412
Accrued vacation 2,710 2,417
Accrued insurance 2,040 1,832
Accrued interest 2,106 1,271
Accrued ad valorem and franchise taxes 1,573 1,003
Accrued commissions 418 461
Other accrued liabilities 1,152 1,520
Total accrued liabilities 17,021 17,559
Other long-term liabilities:    
Deferred rent 836 966
Incentive compensation 962 1,287
Contingent consideration 1,045 1,125
Total other long-term liabilities 2,843 3,378
Term Loan [Member] | Credit Agreement [Member]    
Current portion of long-term debt and capital lease obligations:    
Long-term Debt 0 15,000
Acquisition Debt, Deferred Purchase Price [Member] | Notes Payable, Other Payables [Member]    
Current portion of long-term debt and capital lease obligations:    
Long-term Debt 2,072 1,927
Federal income taxes receivable    
Other current assets:    
State income taxes receivable 988 0
State income taxes receivable    
Other current assets:    
State income taxes receivable $ 1,320 $ 889