Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Cash flows from operating activities
Net income	$ 196,650	$ 157,362
Adjustments to reconcile net income to net cash provided by operating activities:
Loss/(gain) on sale of assets and other	2,251	(204)
Depreciation and amortization	33,192	30,088
Noncash lease expense	7,237	6,246
Deferred income taxes	1,197	1,852
Noncash compensation related to stock plans	13,391	9,459
Provision of doubtful accounts	74	23
Changes in operating assets and liabilities:
Trade accounts receivable	(73,219)	(87,170)
Inventories	(104,223)	(7,199)
Trade accounts payable	15,527	7,825
Other current assets	(11,272)	(618)
Accrued liabilities and other current liabilities	45,924	21,762
Other noncurrent assets and liabilities	(4,631)	(9,808)
Net cash provided by operating activities	122,098	129,618
Cash flows from investing activities
Capital expenditures	(31,285)	(20,879)
Asset acquisitions, net of cash acquired	(218)	(1,425)
Equity method investments	(9,829)	0
Proceeds from sale of property and equipment	132	750
Net cash used in investing activities	(41,200)	(21,554)
Cash flows from financing activities
Repurchase of common stock	(24,125)	(62,679)
Proceeds from lines of credit	8,530	164,330
Repayments of lines of credit and capital leases	(8,632)	(89,347)
Debt issuance costs	(819)	(712)
Dividends paid	(30,815)	(30,164)
Cash paid on behalf of employees for shares withheld	(5,397)	(7,581)
Net cash used in financing activities	(61,258)	(26,153)
Effect of exchange rate changes on cash and cash equivalents	(99)	(656)
Net increase in cash and cash equivalents	19,541	81,255
Cash and cash equivalents at beginning of period	274,639	230,210
Cash and cash equivalents at end of period	294,180	311,465
Noncash activity during the period
Noncash capital expenditures	550	778
Dividends declared but not paid	10,847	10,000
Issuance of Company’s common stock for compensation	$ 692	$ 342