CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Cash flows from operating activities:
Net income	$ 122,904	$ 174,643	$ 101,778
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation and amortization	26,177	24,000	31,209
Equity-based compensation	14,727	14,095	11,871
Asset impairment charges	9,114	0	0
Impairment of investments	0	219	0
Excess tax benefit from share-based compensation	(1,578)	(1,392)	(244)
Loss on sale of property and equipment	311	284	(58)
Gain on sale of business	(930)	(68,745)	0
Deferred income taxes	8,067	10,796	(1,347)
Changes in assets and liabilities, net of businesses acquired:
Accounts receivable, net	(8,647)	(3,269)	(4,603)
Inventories, net	11,530	(19,545)	(33,884)
Other assets	7,304	(12,721)	(2,615)
Accounts payable	(14,605)	(5,439)	6,619
Accrued liabilities	(4,193)	(11,086)	15,386
Deferred revenue	4,351	(14,131)	3,414
Income taxes	16,335	(14,983)	16,980
Other operating activities	(7,536)	5,582	(2,669)
Net cash provided by operating activities	183,331	78,308	141,837
Cash flows from investing activities:
Purchases of property and equipment	(22,443)	(26,918)	(30,721)
Proceeds from the sale of business	27,580	161,206	0
Acquisition of businesses, net of cash acquired	(59,876)	0	0
Acquisition of intangible assets	(3,500)	(1,232)	(3,497)
Purchases of long-term investments	(9,125)	0	0
Purchases of investments and marketable securities	(347,609)	(991,633)	(382,091)
Maturities of investments and marketable securities	145,028	607,996	274,208
Proceeds from sales of investments and marketable securities	164,410	303,801	102,485
Net cash provided by (used in) investing activities	(105,535)	53,220	(39,616)
Cash flows from financing activities:
Purchase of treasury stock	(54,373)	(160,200)	(102,091)
Proceeds from exercise of stock options and stock purchase plan purchases	3,361	13,009	8,975
Excess tax benefit from equity-based compensation	1,578	1,392	244
Net cash used in financing activities	(49,434)	(145,799)	(92,872)
Effect of exchange rate changes on cash	(40)	1,835	562
Net increase (decrease) in cash and cash equivalents	28,322	(12,436)	9,911
Cash balance of discontinued operations at beginning of period	0	1,301	1,694
Cash balance of discontinued operations at end of period	0	0	1,301
Cash and cash equivalents at beginning of period	36,418	47,553	37,249
Cash and cash equivalents at end of period	64,740	36,418	47,553
Supplemental disclosures of cash flow information:
Income taxes paid	$ 20,059	$ 65,364	$ 26,563