Accounts Receivable

3 Months Ended

Mar. 31, 2020

Receivables [Abstract]

Accounts Receivable

3.     Accounts Receivable

(table only in thousands)	March 31, 2020			December 31, 2019
Contract receivables	$	47,128		$	58,881
Trade receivables		11,073			12,135
Allowance for doubtful accounts		(2,563	)		(2,582	)
Total accounts receivable	$	55,638		$	68,434

Balances billed but not paid by customers under retainage provisions in contracts within the Condensed Consolidated Balance Sheets amounted to approximately $1.1 million and $0.9 million at March 31, 2020 and December 31, 2019, respectively. Retainage receivables on contracts in progress are generally collected within a year after contract completion.

Bad debt expense was approximately $46,000 and $0.1 million for the three-month periods ended March 31, 2020 and 2019, respectively.