Quarterly report pursuant to Section 13 or 15(d)

Basis of Presentation and Significant Accounting Policies (Tables)

v3.10.0.1
Basis of Presentation and Significant Accounting Policies (Tables)
 6 Months Ended
Jun. 30, 2018
Accounting Policies [Abstract]  
Schedule of allowance for doubtful accounts receivable
Following is a roll forward of the allowance for doubtful accounts for the year ended December 31, 2017 and the six months ended June 30, 2018 (in thousands):

Balance, January 1, 2017
 
$
5,377

Additions charged to expense
 
16,206

Additions other
 
179

Deductions for uncollectible receivables written off
 
(25
)
Balance, December 31, 2017
 
21,737

Additions charged to expense
 
53,790

Deductions for uncollectible receivables written off
 
(1,758
)
Balance, June 30, 2018
 
$
73,769

Schedules of concentration of risk
Following is a summary of our significant customers based on percentages of total accounts receivable balances at June 30, 2018 and December 31, 2017 and percentages of total revenues derived for the three and six months ended June 30, 2018 and 2017:
 
REVENUES
 
ACCOUNTS RECEIVABLE
 
Three Months Ended June 30,
 
Six Months Ended June 30,
 
At June 30,
At December 31,
 
2018
2017
 
2018
2017
 
2018
2017
Customer A(a)
65
%
—
%
 
65
%
—
%
 
59
%
56
%
Customer B(b)
9
%
59
%
 
11
%
59
%
 
9
%
12
%
a.
Customer A is a third-party customer. Revenues and the related accounts receivable balances earned from Customer A were derived from the Company's infrastructure services segment.
b.
Customer B is a related party customer. Revenues and the related accounts receivable balances earned from Customer B were derived from the Company's pressure pumping services segment, natural sand proppant services segment, contract land and directional drilling services segment and other businesses.