Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Taxes Paid	$ 38,938	$ 45,982	$ 52,403
Cash flows from operating activities:
Net Income	8,788	55,217	86,539
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	35,590	32,854	16,775
Purchase premium amortization/discount accretion on investments, net	11	1,103	2,490
Non-cash stock-based compensation	20,014	17,462	14,372
Income tax impact associated with stock option exercises	(481)	428	1,121
Gain on Sale of Investments	0	0	(3,126)
Excess tax benefit from stock-based compensation	(485)	(767)	(1,552)
Goodwill impairment charges	74,196	0	0
Intangibles Impairment charges	0	2,000	0
Deferred income taxes	(20,261)	(7,927)	(2,545)
Changes in assets and liabilities, net of effect of acquisitions:
Accounts receivable	(9,205)	(10,470)	5,317
Inventories	1,573	(46,679)	(10,590)
Prepaid expenses and other assets	(7,905)	(4,615)	2,619
Accounts payable	(8,236)	36,250	(30,615)
Accrued employee compensation	5,037	(1,787)	(8,782)
Other accrued liabilities	2,574	15,070	3,444
Deferred revenue	5,188	(1,211)	(12,680)
Income taxes payable	2,566	(26)	(7,744)
Net cash provided by operating activities	108,964	86,902	55,043
Cash flows from investing activities:
Purchases of short-term investments	(145,186)	(153,464)	(369,939)
Proceeds from maturities of short-term investments	134,827	275,406	284,418
Purchase of property and equipment	(19,338)	(18,050)	(14,762)
Payments for patents	0	(275)	(1,400)
Proceeds from sale of cost method investment	0	3,890	0
Payments made in connection with business acquisitions, net of cash acquired	(1,050)	(147,240)	(28,625)
Net cash used in investing activities	(30,747)	(39,733)	(130,308)
Cash flows from financing activities:
Purchase and retirement of treasury stock	(93,218)	(63,585)	(850)
Proceeds from exercise of stock options	9,979	7,487	12,700
Proceeds from issuance of common stock under employee stock purchase plan	2,762	2,139	1,997
Excess tax benefit from stock-based compensation	485	767	1,552
Net cash provided by (used in) financing activities	(79,992)	(53,192)	15,399
Net increase (decrease) in cash and cash equivalents	(1,775)	(6,023)	(59,866)
Cash and cash equivalents, at beginning of period	143,009	149,032	208,898
Cash and cash equivalents, at end of period	$ 141,234	$ 143,009	$ 149,032