Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Cash flows from operating activities:
Net income	$ 79,566	$ 45,413
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	9,115	5,529
Amortization of premium on available-for-sale securities	1,348	813
(Gain) loss on deferred compensation plan investments	2,192	(1,177)
Deferred taxes, net	(381)	1,004
Stock-based compensation expense	39,811	28,583
Other	5	5
Changes in operating assets and liabilities:
Accounts receivable	(15,506)	(17,236)
Inventories	(51,797)	(18,151)
Other assets	(5,916)	(2,215)
Accounts payable	(4,177)	13,513
Accrued compensation and related benefits	27,382	10,609
Income tax liabilities	16,017	1,800
Other accrued liabilities	9,760	8,567
Net cash provided by operating activities	107,419	77,057
Cash flows from investing activities:
Purchases of property and equipment	(26,877)	(18,970)
Purchases of short-term investments	(16,243)	(201,517)
Maturities and sales of short-term investments	32,242	38,472
Sales of long-term investments	25	25
Contributions to deferred compensation plan, net	(760)	(876)
Net cash used in investing activities	(11,613)	(182,866)
Cash flows from financing activities:
Property and equipment purchased on extended payment terms	(528)	(563)
Proceeds from common stock issued under the employee equity incentive plan	2,318	10,744
Proceeds from common stock issued under the employee stock purchase plan	2,786	2,293
Dividends and dividend equivalents paid	(28,825)	(23,467)
Net cash used in financing activities	(24,249)	(10,993)
Effect of change in exchange rates	(220)	218
Net increase (decrease) in cash, cash equivalents and restricted cash	71,337	(116,584)
Cash, cash equivalents and restricted cash, beginning of period	189,389	335,071
Cash, cash equivalents and restricted cash, end of period	260,726	218,487
Supplemental disclosures for cash flow information:
Cash paid for taxes	244	377
Non-cash investing and financing activities:
Liability accrued for property and equipment purchases	6,122	12,963
Liability accrued for dividends and dividend equivalents	$ 36,611	$ 29,000