Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Cash Flows from Operating Activities
Net income	$ 54,121	$ 64,169
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	14,799	14,656
Stock option expense	8,482	7,451
Benefit for deferred income taxes	(3,195)	(4,047)
Noncash long-term incentive compensation	2,024	1,185
Amortization of debt issuance costs	95	76
Changes in operating assets and liabilities:
(Increase)/decrease in accounts receivable	(14,318)	19,610
Increase in inventories	(391)	(431)
Decrease in prepaid expenses	1,236	3,099
Decrease in accounts payable and other current liabilities	(24,109)	(30,332)
Change in current income taxes	19,118	23,530
Net change in lease assets and liabilities	(632)	743
Increase in other assets	(2,173)	(1,562)
Increase in other liabilities	5,313	2,958
Other sources/(uses)	122	(15)
Net cash provided by operating activities	60,492	101,090
Cash Flows from Investing Activities
Capital expenditures	(17,020)	(12,649)
Proceeds from sale of fixed assets	146	485
Business combinations, net of cash acquired		(1,650)
Other uses	(139)	(134)
Net cash used by investing activities	(17,013)	(13,948)
Cash Flows from Financing Activities
Payments on long-term debt	(76,250)
Proceeds from exercise of stock options	25,680	7,692
Dividends paid	(5,685)	(5,322)
Capital stock surrendered to pay taxes on stock-based compensation	(3,166)	(4,893)
Payments on revolving line of credit		(86,500)
Purchases of treasury stock		(27,794)
Proceeds from revolving line of credit		21,500
Change in cash overdraft payable		(7,051)
Other (uses)/sources	(130)	491
Net cash used by financing activities	(59,551)	(101,877)
Decrease in Cash and Cash Equivalents	(16,072)	(14,735)
Cash and cash equivalents at beginning of period	74,126	32,895
Cash and cash equivalents at end of period	$ 58,054	$ 18,160