Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cash flows from operating activities:
Net income	$ 78,299	$ 70,714	$ 61,570
Adjustments to reconcile net income to net cash provided by operating activities:
Gain on sale of operations, net of tax	509	(417)	(1,025)
Depreciation and amortization expense	23,139	22,345	23,675
Bad debt expense, net of recoveries	4,409	2,415	3,665
Adjustment to contingent earnout liability, net	(629)	1,599	2,617
Deferred income taxes	(770)	9,695	5,775
Employee stock awards	8,869	7,254	6,866
Excess tax benefits from share based payment arrangements	(2,394)	(4,773)	(3,260)
Other, net	485	1,077	400
Changes in assets and liabilities, net of acquisitions and divestitures:
Accounts receivable, net	6,714	(15,529)	(10,668)
Other assets	1,472	907	(3,344)
Accounts payable	(8,800)	9,829	974
Income taxes payable	2,158	(687)	426
Accrued personnel costs	19,788	(4,093)	17,901
Other liabilities	13,667	(1,813)	(140)
Net cash provided by continuing operations	146,916	98,523	105,432
Operating cash flows used in discontinued operations	(71)	(338)	(184)
Net cash provided by operating activities	146,845	98,185	105,248
Cash flows from investing activities:
Business acquisitions and purchases of client lists, net of cash acquired	(71,430)	(11,744)	(29,080)
Purchases of client fund investments	(3,447)	(27,216)	(18,426)
Proceeds from the sales and maturities of client fund investments	37,487	23,958	12,238
Additions to property and equipment	(11,576)	(13,873)	(14,624)
Other, net	2,560	1,190	2,316
Net cash used in investing activities	(46,406)	(27,685)	(47,576)
Cash flows from financing activities:
Proceeds from bank debt	592,354	648,648	690,173
Payment of bank debt	(589,854)	(678,648)	(733,173)
Payment for acquisition of treasury stock	(58,536)	(27,163)	(17,484)
(Decrease) increase in client funds obligations	(13,747)	10,069	(41,509)
Payment of contingent consideration of acquisitions	(12,859)	(17,457)	(11,787)
Proceeds from exercise of stock options	6,486	10,608	6,291
Other, net	(453)	(606)	(1,891)
Net cash used in financing activities	(76,609)	(54,549)	(109,380)
Net increase (decrease) in cash, cash equivalents and restricted cash	23,830	15,951	(51,708)
Cash, cash equivalents and restricted cash at beginning of year	146,505	130,554	182,262
Cash, cash equivalents and restricted cash at end of year	170,335	146,505	130,554
Reconciliation of cash, cash equivalents and restricted cash to the Consolidated Balance Sheets
Cash, cash equivalents and restricted cash at end of year	170,335	130,554	130,554
Supplemental disclosures of cash flow information:
Cash paid for interest	4,739	5,556	6,340
Cash paid for income taxes, net of income tax refunds	$ 25,939	$ 17,497	$ 15,327