Accounts Receivable

3 Months Ended

Mar. 31, 2016

(5) Accounts Receivable

Accounts receivable (in thousands) consisted of the following, as of:


	March 31,			December 31,
	2016			2015
Billed and billable	$	139,099		$	175,382
Less: unpaid deferred revenue		(78,232	)		(103,403	)

Accounts receivable, gross		60,867			71,979
Less: allowance for doubtful accounts		(4,309	)		(3,825	)

Accounts receivable, net	$	56,558		$	68,154

The Company offsets its accounts receivable and deferred revenue for any unpaid items included in deferred revenue and advance payments.

The Company maintains an allowance for doubtful accounts which represents its best estimate of probable losses inherent in the accounts receivable balances. The Company evaluates specific accounts when it becomes aware that a customer may not be able to meet its financial obligations due to deterioration of its liquidity or financial viability, credit ratings, or bankruptcy. In addition, the Company periodically adjusts this allowance based upon its review and assessment of the aging of receivables.