Accounts Receivable

6 Months Ended

Jun. 30, 2017

Receivables [Abstract]

Accounts Receivable

3. Accounts Receivable

(Table only in thousands)	June 30, 2017			December 31, 2016
Trade receivables	$	13,204		$	11,976
Contract receivables		55,108			72,835
Allowance for doubtful accounts		(2,181	)		(1,749	)
	$	66,131		$	83,062

Balances billed but not paid by customers under retainage provisions in contracts amounted to approximately $3.0 million and $3.2 million at June 30, 2017 and December 31, 2016, respectively. Retainage receivables on contracts in progress are generally collected within a year after contract completion.

The provision for doubtful accounts was $0.7 million and $0.2 million for the three-month periods ended June 30, 2017 and 2016, respectively, and $1.0 million and $0.3 million for the six-month periods ended June 30, 2017 and 2016, respectively.