Condensed Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
OPERATING ACTIVITIES
Net income	$ 135,735	$ 47,950
Adjustments to reconcile net income to net cash provided by operating activities:
Share-based compensation expense	10,295	5,406
Deferred income taxes	387	357
Amortization of investments	1,185	874
Depreciation and amortization	951	751
Impairment of purchased technology and goodwill	987	299
Loss on disposal of property and equipment	33	11
Changes in operating assets and liabilities:
Accounts receivable	(34,478)	(17,087)
Inventories	(1,928)	(1,587)
Prepaid income taxes	5,474	2,964
Prepaid expenses and other current assets	(2,002)	(936)
Accounts payable	6,091	1,093
Accrued compensation	4,412	3,500
Sales-related reserves	4,266	9,728
Other accrued liabilities	4,200	860
Other non-current liabilities	(259)	(81)
Net cash flows provided by operating activities	135,349	54,102
INVESTING ACTIVITIES
Purchase of property and equipment	(651)	(1,470)
Purchase of short-term investments	(122,776)	(84,125)
Proceeds from maturities of short-term investments	167,524	87,871
Deposits and other assets	(14)	9
Net cash flows provided by investing activities	44,083	2,285
FINANCING ACTIVITIES
Income tax benefit realized from share-based compensation plans	6,678	6,889
Issuance of common stock, net	4,698	3,771
Repurchase of common stock	(243,201)	(11,453)
Net cash flows used in financing activities	(231,825)	(793)
(Decrease) increase in cash and cash equivalents	(52,393)	55,594
Cash and cash equivalents at beginning of period	88,469	41,508
Cash and cash equivalents at end of period	36,076	97,102
Supplemental Disclosures of Cash Flow Information:
Cash paid for interest	17	11
Cash paid for income taxes	$ 54,024	$ 12,973