Accounts Receivable

12 Months Ended

Dec. 31, 2021

Receivables [Abstract]

Accounts Receivable

3.Accounts Receivable

Accounts receivable consisted of the following:

	December 31,
(table only in thousands)	2021			2020
Contract receivables	$	65,932		$	57,435
Trade receivables		12,537			8,721
Allowance for doubtful accounts		(3,478	)		(3,110	)
Total accounts receivable	$	74,991		$	63,046

Balances billed, but not paid by customers under retainage provisions in contracts, amounted to approximately $1.8 million and $1.5 million at December 31, 2021 and 2020, respectively. Retainage receivables on contracts in progress are generally collected within a year or two subsequent to contract completion, and are recorded in either accounts receivable, net or deferred charges and other assets within the Consolidated Balance Sheets depending on timing of expected collection.

Provision for doubtful accounts was $0.7 million, $0.9 million and $0.3 million during 2021, 2020 and 2021, respectively, while accounts charged to the allowance were $0.3 million, $0.4 million and $0.6 million during 2021, 2020 and 2019, respectively.