Accounts Receivable

12 Months Ended

Dec. 31, 2017

Receivables [Abstract]

Accounts Receivable

5.     ACCOUNTS RECEIVABLE:

Included in accounts receivable are unbilled amounts totaling approximately $3.4 million and $2.7 million at December 31, 2017 and 2016, respectively, which relate to services performed during the year and billed in the subsequent year. The Company maintains allowances for potential losses which management believes are adequate to absorb any probable losses to be incurred in realizing the accounts receivable amounts recorded in the accompanying consolidated financial statements.

The following are the changes in the allowance for doubtful accounts:

	Year Ended December 31,
	2017			2016			2015
	(In Thousands)
Balance at beginning of year	$	150		$	150		$	150
Provisions for doubtful accounts		30			104			67
Charge-offs, net of recoveries		(30	)		(104	)		(67	)
Balance at end of year	$	150		$	150		$	150