CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 63,496	$ 76,099
Adjustments to reconcile net income to net cash provided by operating activities:
Amortization of trademark	12	12
Depreciation and other amortization	5,048	4,956
Gain on disposal of property and equipment	(2)	(39)
Stock-based compensation	6,959	6,571
(Gain) loss on put option	(83)	1,391
Gain on investments, net	(2,489)	(1,787)
Deferred income taxes	(398)	2,574
Tax benefit from exercise of stock options	(176)	(492)
Effect on cash of changes in operating assets and liabilities:
Accounts receivable	(69,713)	(33,867)
Distributor receivables	(8,314)	(43)
Inventories	(14,080)	(34,128)
Prepaid expenses and other current assets	(10,584)	257
Prepaid income taxes	27,417	(1,216)
Accounts payable	7,479	16,201
Accrued liabilities	9,879	14,058
Accrued promotional allowances	13,939	(34,034)
Accrued distributor terminations	7,372	(76)
Accrued compensation	(5,377)	(3,836)
Income taxes payable	9,270	25,784
Deferred revenue	6,238	(1,615)
Net cash provided by operating activities	45,893	36,770
CASH FLOWS FROM INVESTING ACTIVITIES:
Maturities of held-to-maturity investments	66,344	141,806
Sales of available-for-sale investments		29,891
Sales of trading investments		15,750
Purchases of held-to-maturity investments	(69,464)	(190,635)
Purchases of available-for-sale investments		(2,001)
Purchases of property and equipment	(8,732)	(14,542)
Proceeds from sale of property and equipment	18	164
Additions to intangibles	(3,362)	(749)
(Increase) decrease in other assets	(219)	302
Net cash used in investing activities	(15,415)	(20,014)
CASH FLOWS FROM FINANCING ACTIVITIES:
Principal payments on debt	(296)	(610)
Tax benefit from exercise of stock options	176	492
Issuance of common stock	2,381	2,722
Purchases of common stock held in treasury	(13,361)
Net cash (used in) provided by financing activities	(11,100)	2,604
Effect of exchange rate changes on cash and cash equivalents	641	12,747
NET INCREASE IN CASH AND CASH EQUIVALENTS	20,019	32,107
CASH AND CASH EQUIVALENTS, beginning of period	222,514	359,331
CASH AND CASH EQUIVALENTS, end of period	242,533	391,438
Cash paid during the period for:
Interest	5	14
Income taxes	$ 5,663	$ 23,491