Revenue and Accounts Receivable (Tables)

12 Months Ended

Dec. 31, 2020

Revenue and Accounts Receivable [Abstract]

Accounts Receivable Components

The components of accounts receivable and contract assets are as follows (in thousands):

	December 31,
	2020			2019
Billed accounts receivable	$	12,060		$	11,917
Unbilled receivables		19,161			16,745
Allowance for doubtful accounts		(308	)		(720	)
Total	$	30,913		$	27,942

Allowance for Doubtful Accounts

The activities in the allowance for doubtful accounts are set forth below (in thousands):

	Balance Beginning of Year		Bad Debt Expenses (1)			Recoveries (2)		Balance End of Year
Year Ended December 31, 2020	$	720	$	(412	)	$	—	$	308
Year Ended December 31, 2019	$	306	$	414		$	—	$	720
Year Ended December 31, 2018	$	411	$	(105	)	$	—	$	306

(1) Accounts receivable reserves and reversal of allowance for subsequent collections, net

(2) Accounts receivable written-off and subsequent recoveries, net

Revenue by Customer Sector

We derived a substantial portion of our revenues from contracts and subcontracts with the U.S. Government. Revenue by customer sector for the last three fiscal years is as follows:

	2020				2019				2018
					(dollar amounts in thousands)
Federal	$	171,677	95.4	%	$	149,257	93.7	%	$	129,279	93.7	%
State & Local, and Commercial		8,240	4.6	%		9,961	6.3	%		8,737	6.3	%
Total	$	179,917	100.0	%	$	159,218	100.0	%	$	138,016	100.0	%