Cash, Cash Equivalents and Marketable Securities

12 Months Ended

Dec. 31, 2018

Cash, Cash Equivalents and Marketable Securities [Abstract]

Cash, Cash Equivalents and Marketable Securities

2. Cash, Cash Equivalents and Marketable Securities

The following table summarizes our investments in cash equivalents and marketable securities held by investment managers and overnight investments:

	December 31,
	2018								2017
(in thousands)	Cash & Cash Equivalents			Marketable Securities		Total			Cash & Cash Equivalents			Marketable Securities		Total
Overnight holdings	$	311,158		$	—	$	311,158		$	338,112		$	—	$	338,112
Investments holdings	16,711			60,781		77,492			22,634			1,960		24,594
Cash in demand accounts	33,207			—		33,207			26,700			—		26,700
Outstanding checks	(34,303		)	—		(34,303		)	(33,186		)	—		(33,186		)
Total	$	326,773		$	60,781	$	387,554		$	354,260		$	1,960	$	356,220

Our cash and overnight holdings fluctuate based on the timing of the client’s payroll processing cycle. Included in the cash balance as of December 31, 2018 and December 31, 2017, are $224.5 million and $271.5 million, respectively, in withholdings associated with federal and state income taxes, employment taxes and other payroll deductions, as well as $34.2 million and $23.6 million, respectively, in client prepayments.