Accounts Receivable and Allowance for Doubtful Accounts
 12 Months Ended
Dec. 31, 2015
Receivables [Abstract]  
Accounts Receivable and Allowance for Doubtful Accounts
ACCOUNTS RECEIVABLE AND ALLOWANCE FOR DOUBTFUL ACCOUNTS

Accounts receivable consisted of the following (in thousands):

 
As of December 31,
 
2015
 
2014
Trade accounts receivable
$
35,039

 
$
42,296

Other receivables
4,244

 
2,793

Costs in excess of billings
1,704

 
—

 
40,987

 
45,089

Less: allowance for doubtful accounts
(467
)
 
(739
)

$
40,520

 
$
44,350



As of December 31, 2015, the Company has one uncompleted contract with costs incurred of $1.9 million and estimated earnings of $0.6 million during the year then ended. Revenues and costs related to such project are included in the Company’s Manufacturing and MRO segment in the accompanying statement of operations. Billings-to-date pursuant to the contract totaled $0.8 million, resulting in $1.7 million of costs and estimated earnings in excess billings as of December 31, 2015.

Customers representing 10% or more of the total trade accounts receivable were as follows:

 
As of December 31,
 
2015
 
2014
Customer A
14.0
%
 
14.4
%
Customer B
11.9

 
11.8

Customer C
11.2

 
—


37.1
%
 
26.2
%


Activity in the allowance for doubtful accounts was as follows (in thousands):
 
Years Ended December 31,

2015
 
2014
 
2013
Allowance for doubtful accounts at beginning of year
$
739

 
$
991

 
$
460

Provisions
317

 
137

 
634

Amounts written-off, net of recoveries
(589
)
 
(389
)
 
(103
)
Allowance for doubtful accounts at end of year
$
467

 
$
739

 
$
991


During the years ended December 31, 2015 and 2013, the Company had bad debt expense of $5.1 million and $0.7 million, respectively, with bad debt recoveries of $0.2 million during the year ended December 31, 2014. During the fourth quarter of 2015, the Company deemed the collection of a non-current account receivable to be doubtful, which was classified in other assets in the consolidated balance sheet at December 31, 2014. Accordingly, the Company charged to expense the doubtful non-current account receivable balance in the amount of $4.8 million, which is included in bad debt expense for the year ended December 31, 2015.