Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Cash flows from operating activities:
Net income	$ 89,382	$ 58,816
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization expense	16,465	12,876
Gain on sale of operations, net	(135)	(6,385)
Bad debt expense, net of recoveries	1,263	265
Adjustment to contingent earnout liability	1,478	753
Stock-based compensation expense	6,428	5,454
Deferred income taxes	4,688	5,360
Other, net	211	(478)
Changes in assets and liabilities, net of acquisitions and divestitures:
Accounts receivable, net	(138,658)	(69,363)
Other assets	(1,696)	(11,279)
Accounts payable	57,837	36,574
Income taxes payable	11,252	(769)
Accrued personnel costs	(11,176)	(7,634)
Other liabilities	(8,822)	42,117
Operating cash flows provided by continuing operations	28,517	66,307
Operating cash flows used in discontinued operations	(9)	(13)
Net cash provided by operating activities	28,508	66,294
Cash flows from investing activities:
Business acquisitions and purchases of client lists, net of cash acquired	(72,469)	(43,172)
Purchases of client fund investments	(18,271)	(7,900)
Proceeds from the sales and maturities of client fund investments	8,505	7,965
Proceeds from sales of divested operations	190	9,785
Change in funds held for clients	(2,468)	(4,029)
Additions to property and equipment	(3,640)	(3,258)
Other, net	(1,603)	472
Net cash used in investing activities	(89,756)	(40,137)
Cash flows from financing activities:
Proceeds from bank debt	447,300	431,700
Payment of bank debt	(336,600)	(376,400)
Payment for acquisition of treasury stock	(34,354)	(64,506)
Indirect repurchase of shares for minimum tax withholding	(7,289)	(3,037)
Changes in client funds obligations	29,014	(27,823)
Proceeds from exercise of stock options	3,896	5,448
Payment of contingent consideration for acquisitions	(8,240)	(7,850)
Other, net	(2,072)	(114)
Net cash provided by (used in) financing activities	91,655	(42,582)
Net increase (decrease) in cash, cash equivalents and restricted cash	30,407	(16,425)
Cash, cash equivalents and restricted cash at beginning of year	150,474	170,335
Cash, cash equivalents and restricted cash at end of period	180,881	153,910
Reconciliation of cash, cash equivalents and restricted cash to the   Condensed Consolidated Balance Sheets:
Cash and cash equivalents	3,881	4,677
Restricted cash	42,188	39,268
Cash equivalents included in funds held for clients	134,812	109,965
Total cash, cash equivalents and restricted cash	$ 180,881	$ 153,910