CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Cash flows from operating activities:
Net income	$ 134,358	$ 122,904	$ 174,643
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation and amortization	32,110	26,177	24,000
Equity-based compensation	13,109	14,727	14,095
Asset impairment charges	0	9,114	0
Impairment of investments	0	0	219
Excess tax benefit from share-based compensation	(4,277)	(1,578)	(1,392)
Loss on sale of property and equipment	224	311	284
Gain on sale of business	(201)	(930)	(68,745)
Deferred income taxes	7,929	8,067	10,796
Changes in assets and liabilities, net of businesses acquired:
Accounts receivable, net	(6,488)	(8,647)	(3,269)
Inventories, net	2,743	11,530	(19,545)
Other assets	(342)	7,304	(12,721)
Accounts payable	7,544	(14,605)	(5,439)
Accrued liabilities	6,220	(4,193)	(11,086)
Deferred revenue	2,133	4,351	(14,131)
Income taxes	(242)	16,335	(14,983)
Other operating activities	(54)	(7,536)	5,582
Net cash provided by operating activities	194,766	183,331	78,308
Cash flows from investing activities:
Purchases of property and equipment	(20,211)	(22,443)	(26,918)
Proceeds from the sale of business	0	27,580	161,206
Acquisition of businesses, net of cash acquired	(95,328)	(59,876)	0
Acquisition of intangible assets	(1,500)	(3,500)	(1,232)
Purchases of long-term investments	(12,021)	(9,125)	0
Purchases of investments and marketable securities	(410,283)	(347,609)	(991,633)
Maturities of investments and marketable securities	49,453	145,028	607,996
Proceeds from sales of investments and marketable securities	336,741	164,410	303,801
Net cash provided by (used in) investing activities	(153,149)	(105,535)	53,220
Cash flows from financing activities:
Purchase of treasury stock	(63,102)	(54,373)	(160,200)
Proceeds from exercise of stock options and stock purchase plan purchases	14,652	3,361	13,009
Excess tax benefit from equity-based compensation	4,277	1,578	1,392
Net cash used in financing activities	(44,173)	(49,434)	(145,799)
Effect of exchange rate changes on cash	643	(40)	1,835
Net increase (decrease) in cash and cash equivalents	(1,913)	28,322	(12,436)
Cash balance of discontinued operations at beginning of period	0	0	1,301
Cash balance of discontinued operations at end of period	0	0	0
Cash and cash equivalents at beginning of period	64,740	36,418	47,553
Cash and cash equivalents at end of period	62,827	64,740	36,418
Supplemental disclosures of cash flow information:
Income taxes paid	$ 18,418	$ 20,059	$ 65,364