Consolidated Statements Of Cash Flows (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Cash flows from operating activities:
Net income	$ 174,643,000	$ 101,778,000	$ 47,104,000
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	24,000,000	31,209,000	32,913,000
Equity-based compensation	14,095,000	11,871,000	11,467,000
Asset impairment charges	0	0	(1,058,000)
Impairment of investments	219,000	0	958,000
Excess tax benefit from share-based compensation	(1,392,000)	(244,000)	(13,000)
Loss (gain) on sale of fixed assets	284,000	(58,000)	829,000
Gain on sale of business	(68,745,000)	0	0
Deferred income taxes	10,796,000	(1,347,000)	12,550,000
Changes in assets and liabilities, net of businesses acquired:
Accounts receivable, net	(3,269,000)	(4,603,000)	8,747,000
Inventories, net	(19,545,000)	(33,884,000)	22,315,000
Other assets	(11,408,000)	(3,993,000)	(733,000)
Accounts payable	(5,439,000)	6,619,000	(16,105,000)
Accrued liabilities	(11,086,000)	15,386,000	(16,315,000)
Deferred revenue	(14,131,000)	3,414,000	4,966,000
Income taxes	(14,983,000)	16,980,000	(2,008,000)
Other operating activities	5,582,000	(2,669,000)	81,000
Net cash provided by operating activities	79,621,000	140,459,000	105,698,000
Cash flows from investing activities:
Purchases of property and equipment	(26,918,000)	(30,721,000)	(24,890,000)
Proceeds from the sale of businesses	161,206,000	0	0
Acquisition of intangible assets	(1,232,000)	(3,497,000)	(425,000)
Purchases of investments and marketable securities	(991,633,000)	(382,091,000)	(329,292,000)
Maturities of investments and marketable securities	607,996,000	274,208,000	257,936,000
Proceeds from sales of investments	303,801,000	102,485,000	56,020,000
Net cash provided by (used in) investing activities	53,220,000	(39,616,000)	(40,651,000)
Cash flows from financing activities:
Purchase of treasury stock	(160,200,000)	(102,091,000)	(65,445,000)
Proceeds from exercise of stock options and stock purchase plan purchases	13,009,000	8,975,000	4,972,000
Excess tax benefit from equity-based compensation	1,392,000	244,000	13,000
Net cash used in financing activities	(145,799,000)	(92,872,000)	(60,460,000)
Effect of exchange rate changes on cash	1,835,000	562,000	1,089,000
Net increase (decrease) in cash and cash equivalents	(11,123,000)	8,533,000	5,676,000
Cash balance of discontinued operations at beginning of period	1,301,000	1,694,000	3,440,000
Less: Cash balance of discontinued operations at end of period	0	1,301,000	1,694,000
Cash and cash equivalents at beginning of period	46,175,000	37,249,000	29,827,000
Cash and cash equivalents at end of period	36,353,000	46,175,000	37,249,000
Supplemental disclosures of cash flow information:
Income taxes paid	$ 65,364,000	$ 26,563,000	$ 10,742,000