Cash, Cash Equivalents and Marketable Securities (Notes)

3 Months Ended

Mar. 31, 2019

Cash, Cash Equivalents and Marketable Securities [Abstract]

Cash, Cash Equivalents and Marketable Securities

3. Cash, Cash Equivalents and Marketable Securities

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

	March 31, 2019								December 31, 2018
(in thousands)	Cash & Cash Equivalents			Marketable Securities		Total			Cash & Cash Equivalents			Marketable Securities		Total
Overnight holdings	$	366,128		$	—	$	366,128		$	311,158		$	—	$	311,158
Investment holdings	24,489			53,599		78,088			16,711			60,781		77,492
Cash in demand accounts	25,809			—		25,809			33,207			—		33,207
Outstanding checks	(17,490		)	—		(17,490		)	(34,303		)	—		(34,303		)
Total	$	398,936		$	53,599	$	452,535		$	326,773		$	60,781	$	387,554

Our cash and overnight holdings fluctuate based on the timing of clients’ payroll processing cycles. Included in the cash, cash equivalents and marketable securities at March 31, 2019 and December 31, 2018 are $279.6 million and $224.5 million, respectively, of funds associated with federal and state income tax withholdings, employment taxes and other payroll deductions, as well as $32.4 million and $34.2 million in client prepayments, respectively.