Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Cash flows from operating activities:
Net income	$ 58,127	$ 50,209
Adjustments to reconcile net income to net cash used in operating activities:
Depreciation and amortization expense	8,173	6,252
Bad debt expense, net of recoveries	549	58
Adjustment to contingent earnout liability	642	660
Stock-based compensation expense	3,689	2,855
Deferred income taxes	2,944	3,348
Other, net	52	96
Changes in assets and liabilities, net of acquisitions and divestitures:
Accounts receivable, net	(93,222)	(54,651)
Other assets	(2,441)	(997)
Accounts payable	3,370	(4,873)
Income taxes payable	16,100	11,805
Accrued personnel costs	(39,243)	(29,755)
Other liabilities	(9,626)	172
Operating cash flows used in continuing operations	(50,886)	(14,821)
Operating cash flows used in discontinued operations	(4)	(6)
Net cash used in operating activities	(50,890)	(14,827)
Cash flows from investing activities:
Business acquisitions and purchases of client lists, net of cash acquired	(72,469)	(2,012)
Purchases of client fund investments	(8,450)	0
Proceeds from the sales and maturities of client fund investments	2,370	3,090
Proceeds from sales of divested operations	55	0
Change in funds held for clients	85	83
Additions to property and equipment	(833)	(1,146)
Other, net	(2,289)	214
Net cash (used in) provided by investing activities	(81,531)	229
Cash flows from financing activities:
Proceeds from bank debt	268,000	235,700
Payment of bank debt	(124,400)	(181,700)
Payment for acquisition of treasury stock	(5,199)	(31,678)
Indirect repurchase of shares for minimum tax withholding	(6,373)	(1,464)
Changes in client funds obligations	42,499	(26,499)
Proceeds from exercise of stock options	3,224	4,408
Payment of contingent consideration for acquisitions	(7,305)	(1,670)
Other, net	0	(57)
Net cash provided by (used in) financing activities	170,446	(2,960)
Net increase (decrease) in cash, cash equivalents and restricted cash	38,025	(17,558)
Cash, cash equivalents and restricted cash at beginning of year	150,474	170,335
Cash, cash equivalents and restricted cash at end of period	188,499	152,777
Reconciliation of cash, cash equivalents and restricted cash to the   Condensed Consolidated Balance Sheets:
Cash and cash equivalents	558	6,778
Restricted cash	33,394	27,618
Cash equivalents included in funds held for clients	154,547	118,381
Total cash, cash equivalents and restricted cash	$ 188,499	$ 152,777