Accounts Receivable (Tables)

12 Months Ended

Dec. 31, 2017

Accounts Receivable Additional Disclosures [Abstract]

Unbilled accounts receivable

We make an accrual at the end of each accounting period for our obligations associated with the earned but unpaid wages of our worksite employees and for the accrued gross billings associated with such wages. These accruals are included in accrued worksite employee payroll cost and unbilled accounts receivable; however, these amounts are presented net in the Consolidated Statements of Operations. We generally require clients to pay invoices for service fees no later than one day prior to the applicable payroll date. As such, we generally do not require collateral. Client prepayments directly attributable to unbilled accounts receivable have been netted against such receivables as the gross billings have been earned and the payroll cost has been incurred, thus we have the legal right of offset for these amounts. Unbilled accounts receivable consisted of the following:

	December 31,
	2017			2016
	(in thousands)
Accrued worksite employee payroll cost	$	267,402		$	215,214
Unbilled revenues	74,632			61,041
Customer prepayments	(23,603		)	(21,256		)
Unbilled accounts receivable	$	318,431		$	254,999