Basis of Presentation and Significant Accounting Policies (Tables)

9 Months Ended

Sep. 30, 2020

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, 2019 and the nine months ended September 30, 2020 (in thousands):

Balance, January 1, 2019	$	5,198
Additions charged to bad debt expense	1,771
Recoveries of receivables previously charged to bad debt expense	(337)
Deductions for uncollectible receivables written off	(1,478)
Balance, December 31, 2019	5,154
Additions charged to bad debt expense	2,935
Additions charged to other expense	2,127
Recoveries of receivables previously charged to bad debt expense	(629)
Deductions for uncollectible receivables written off	(2,344)
Balance, September 30, 2020	$	7,243

Schedules of concentration of risk

Following is a summary of our significant customers based on percentages of total accounts receivable balances at September 30, 2020 and December 31, 2019 and percentages of total revenues derived for the three and nine months ended September 30, 2020 and 2019:

	REVENUES								ACCOUNTS RECEIVABLE
	Three Months Ended September 30,				Nine Months Ended September 30,				At September 30,		At December 31,
	2020		2019		2020		2019		2020		2019
Customer A(a)	—	%	—	%	—	%	17	%	71	%	73	%
Customer B(b)	15	%	15	%	18	%	22	%	9	%	2	%
Customer C(c)	8	%	4	%	10	%	4	%	2	%	3	%

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. Accounts receivable for Customer A also includes receivables due for interest charged on delinquent accounts receivable.

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 and other businesses. Accounts receivable for Customer B also includes receivables due for interest charged on delinquent accounts receivable.

c.Customer C is a third-party customer. Revenues and the related accounts receivable balances earned from Customer C were derived from the Company's infrastructure services segment.