Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Statement of Cash Flows [Abstract]
Net income	$ 50,387	$ 36,826
Adjustments to reconcile net income to net cash provided by operating activities:
Loss/(gain) on sale of assets and other	333	(58)
Depreciation and amortization	11,225	9,734
Noncash lease expense	2,393	1,997
Deferred income taxes	314	1,430
Noncash compensation related to stock plans	6,542	277
Provision of doubtful accounts	(215)	721
Changes in operating assets and liabilities:
Trade accounts receivable	(62,660)	(32,161)
Inventories	(14,750)	(5,962)
Trade accounts payable	17,301	11,018
Other current assets	(14,109)	(6,821)
Accrued liabilities and other current liabilities	22,126	(4,927)
Other noncurrent assets and liabilities	(1,054)	651
Net cash provided by operating activities	17,833	12,725
Cash flows from investing activities
Capital expenditures	(10,505)	(6,795)
Invest in equity investments	(5,329)	0
Proceeds from sale of property and equipment	105	561
Net cash used in investing activities	(15,729)	(6,234)
Cash flows from financing activities
Repurchase of common stock	0	(62,679)
Proceeds from lines of credit	0	154,529
Repayments of lines of credit and capital leases	(192)	(5,415)
Dividends paid	(9,967)	(10,169)
Cash paid on behalf of employees for shares withheld	(5,263)	(7,699)
Net cash used by in financing activities	(15,422)	68,567
Effect of exchange rate changes on cash and cash equivalents	(3,893)	(3,527)
Net (decrease) increase in cash and cash equivalents	(17,211)	71,531
Cash and cash equivalents at beginning of period	274,639	230,210
Cash and cash equivalents at end of period	257,428	301,741
Noncash activity during the period
Noncash capital expenditures	1,526	289
Dividends declared but not paid	9,967	10,204
Issuance of Company’s common stock for compensation	$ 692	$ 322