Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Cash flows from operating activities:
Net income	$ 39,471	$ 38,386	$ 34,243
Adjustments to reconcile net income to net cash provided by (used in) operating activities
Depreciation and amortization	14,585	14,344	15,316
Bad debt provision	46,760	35,604	31,969
Deferred income taxes	(2,944)	(4,820)	4,907
Share-based compensation expense	9,165	8,985	9,214
Amortization of premium on marketable securities	1,504	2,144	2,219
Unrealized gain on deferred compensation fund investments	(8,168)	(6,645)	9,422
Changes in other long-term liabilities	(564)	(1,154)	(2,353)
Net loss on disposals of property and equipment	654	818	1,138
Share of losses from equity method investment	532	0	0
Changes in operating assets and liabilities:
Accounts and notes receivable	(61,809)	(74,559)	(78,707)
Inventories and supplies	1,731	2,685	4,851
Prepaid expenses and other assets	704	12,750	9,935
Deferred compensation funding	(534)	(674)	3,913
Accounts payable and other accrued expenses	(9,741)	7,430	(13,748)
Accrued payroll, accrued and withheld payroll taxes	(3,573)	4,186	(23,859)
Income taxes payable	1,190	572	2,184
Accrued insurance claims	(7,362)	(4,329)	(687)
Deferred compensation liability	9,201	7,775	(18,124)
Net cash provided by (used in) operating activities	30,802	43,498	(8,167)
Cash flows from investing activities:
Disposals of property and equipment	211	121	393
Additions to property and equipment	(6,336)	(5,406)	(5,210)
Acquisition of equity method investment	(2,750)	0	0
Purchases of marketable securities	(52,090)	0	(2,875)
Sales of marketable securities	67,012	1,992	10,386
Cash paid for acquisitions	0	0	(114)
Net cash provided by (used in) investing activities	6,047	(3,293)	2,580
Cash flows from financing activities:
Dividends paid	0	0	(63,373)
Reissuance of treasury stock pursuant to Dividend Reinvestment Plan	0	0	106
Proceeds from the exercise of stock options	0	0	410
Purchases of treasury stock	(5,018)	(11,283)	0
(Repayments of) proceeds from short-term borrowings	(25,000)	0	25,000
Payments of statutory withholding on net issuance of restricted stock units	(1,030)	(871)	(1,071)
Net cash used in financing activities	(31,048)	(12,154)	(38,928)
Net increase (decrease) in cash, cash equivalents, and restricted cash equivalents	5,801	28,051	(44,515)
Cash, cash equivalents and restricted cash equivalents at beginning of the period	54,330	26,279	70,794
Cash, cash equivalents and restricted cash equivalents at end of the period	60,131	54,330	26,279
Supplementary cash flow information:
Cash paid for interest	6,491	7,809	2,822
Cash paid for income taxes	$ 15,232	$ 5,585	$ 3,309