Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 134,223	$ 193,069
Short-term marketable securities	271,063	250,378
Accounts receivable, net of allowances of $4,284 and $4,962, respectively	206,307	164,436
Inventories	282,408	237,001
Prepaid expenses and other current assets	23,803	18,417
Income taxes receivable	2,197	1,215
Total current assets	920,001	864,516
Property and equipment, net of accumulated depreciation of $332,917 and $305,575, respectively	236,342	221,076
Long-term marketable securities	503,965	562,475
Intangible assets, net	54,057	68,660
Goodwill	181,774	179,708
Other assets	35,654	36,334
Deferred income taxes	44,719	24,494
Total assets	1,976,512	1,957,263
Current liabilities:
Accounts payable	31,971	21,955
Accrued expenses	88,361	91,168
Income taxes payable	1,308	1,046
Business acquisition liabilities	11,329	11,770
Deferred revenue	12,286	12,025
Payable to broker		2,200
Total current liabilities	145,255	140,164
Business acquisition liabilities, net of current portion	52,965	58,755
Deferred income taxes	1,578	4,314
Other liabilities	12,603	12,642
Total liabilities	212,401	215,875
Commitments and contingencies (Note 15)
Equity:
Additional paid-in capital	606,352	553,787
Accumulated other comprehensive income/(loss)	(32,226)	(6,772)
Retained earnings	1,189,886	1,194,272
Total equity	1,764,111	1,741,388
Total liabilities and equity	1,976,512	1,957,263
Common Class A [Member]
Equity:
Common stock	77	79
Common Class B [Member]
Equity:
Common stock	$ 22	$ 22