Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Cash flows from operating activities:
Net income	$ 50,209	$ 36,848
Adjustments to reconcile net income to net cash used in operating activities:
Depreciation and amortization expense	6,252	5,704
Bad debt expense, net of recoveries	58	2,289
Adjustment to contingent earnout liability	660	(684)
Stock-based compensation expense	2,855	2,023
Excess tax benefits from share based payment arrangements	(2,179)	(501)
Deferred income taxes	3,348	170
Other, net	96	20
Changes in assets and liabilities, net of acquisitions and divestitures:
Accounts receivable, net	(54,651)	(42,566)
Other assets	(997)	(1,237)
Accounts payable	(4,873)	(6,336)
Income taxes payable	13,984	13,665
Accrued personnel costs	(29,755)	(30,201)
Other liabilities	172	2,175
Operating cash flows used in continuing operations	(14,821)	(18,631)
Operating cash flows used in discontinued operations	(6)	(16)
Net cash used in operating activities	(14,827)	(18,647)
Cash flows from investing activities:
Business acquisitions and purchases of client lists, net of cash acquired	(2,012)	(7,848)
Purchases of client fund investments	0	(3,447)
Proceeds from the sales and maturities of client fund investments	3,090	17,118
Increase in funds held for clients	83	822
Additions to property and equipment	(1,146)	(2,641)
Other	214	351
Net cash provided by investing activities	229	4,355
Cash flows from financing activities:
Proceeds from bank debt	235,700	379,754
Payment of bank debt	(181,700)	(102,254)
Payment for acquisition of treasury stock	(33,142)	(29,487)
Decrease in client funds obligations	(26,499)	(38,517)
Proceeds from exercise of stock options	4,408	1,013
Payment of contingent consideration for acquisitions	(1,670)	(2,624)
Other, net	(57)	(113)
Net cash (used in) provided by financing activities	(2,960)	207,772
Net (decrease) increase in cash, cash equivalents and restricted cash	(17,558)	193,480
Cash, cash equivalents and restricted cash at beginning of year	170,335	146,505
Cash, cash equivalents and restricted cash at end of period	152,777	339,985
Reconciliation of cash, cash equivalents and restricted cash to the    Consolidated Balance Sheets:
Total cash, cash equivalents and restricted cash	$ 152,777	$ 339,985