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	$ 111,380	$ 9,977	$ 13,540
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	23,868	19,745	5,777
Deferred income taxes	(3,454)	(228)	7,379
Share-based compensation	35,019	21,412	14,101
Gain on investments	(896)	(15)	(25)
Excess tax benefit from share-based compensation	(5,141)	(2,411)	(1,101)
Changes in assets and liabilities, net of effect of acquisition:
Accounts receivable	(10,301)	(15,899)	525
Inventories	(19,436)	(8,639)	(2,951)
Prepaid expenses and other assets	(3,239)	(513)	689
Accounts payable	3,430	21,065	(2,249)
Accrued liabilities and other liabilities	51,259	18,645	5,547
Net cash provided by operating activities	182,489	63,139	41,232
Cash flows from investing activities:
Acquisition of Voltaire Ltd., net of cash acquired of $3,961		(203,704)
Purchase of severance-related insurance policies	(783)	(832)	(789)
Purchase of short-term investments	(328,998)	(45,600)	(182,615)
Proceeds from sales of short-term investments	14,860	149,889	157,377
Proceeds from maturities of short-term investments	64,683	12,128	50,628
Purchase of property and equipment	(30,544)	(24,680)	(11,395)
Increase in restricted cash deposit	1,327	(1,700)
Purchase of equity investment in a private company	(1,424)		(135)
Net cash (used in) provided by investing activities	(280,879)	(114,499)	13,071
Cash flows from financing activities:
Proceeds from public offering, net		104,201
Principal payments on capital lease obligations	(918)	(459)	(528)
Proceeds from exercise of share awards	29,963	18,471	9,478
Excess tax benefit from share-based compensation	5,141	2,411	1,101
Net cash provided by financing activities	34,186	124,624	10,051
Net (decrease) increase in cash and cash equivalents	(64,204)	73,264	64,354
Cash and cash equivalents at beginning of period	181,258	107,994	43,640
Cash and cash equivalents at end of period	117,054	181,258	107,994
Supplemental disclosures of cash flow information
Interest paid			1
Income taxes paid	852	469	1,550
Supplemental disclosure of noncash investing and financing activities
Software acquired under capital leases	4,428	563
Unpaid property and equipment	3,869
Inventory capitalization	1,073		562
Vested share awards issued in connection with the Voltaire acquisition		$ 6,303