Quarterly report pursuant to Section 13 or 15(d)

Summary of Significant Accounting Policies - Accounts Receivable (Details)

v3.7.0.1
Summary of Significant Accounting Policies - Accounts Receivable (Details) - USD ($)
$ in Thousands
 3 Months Ended 12 Months Ended
Mar. 31, 2017
Sep. 30, 2016
Mar. 31, 2016
Dec. 31, 2016
Changes in the Allowance for Doubtful Accounts [Roll Forward]        
Allowance for doubtful accounts, beginning of period $ 7,836   $ 3,729 $ 3,729
Charges to costs and expenses 0   204  
Account write-offs and other (463)   432  
Allowance for doubtful accounts, end of period 7,373   $ 4,365 7,836
Loss contingency, additional exposure 758      
Contracts Receivable Retainage Allowances and Reserves $ 533     $ 887
Minimum        
Changes in the Allowance for Doubtful Accounts [Roll Forward]        
Accounts receivable retainage 5.00%      
Maximum        
Changes in the Allowance for Doubtful Accounts [Roll Forward]        
Accounts receivable retainage 10.00%      
Accounts receivable        
Changes in the Allowance for Doubtful Accounts [Roll Forward]        
Allowance for doubtful accounts receivable, period increase $ 200 $ 2,194    
Costs in Excess of Billings        
Changes in the Allowance for Doubtful Accounts [Roll Forward]        
Allowance for doubtful accounts receivable, period increase 476      
Construction in Progress, Gross        
Changes in the Allowance for Doubtful Accounts [Roll Forward]        
Allowance for doubtful accounts receivable, period increase $ 325