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	$ 51,170	$ 127,877	$ 104,635
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	7,270	6,231	6,124
Amortization of net premiums and discounts on available for sale securities	734	2,021	3,260
Amortization of long term debt financing costs	598	0	0
Amortization of debt discount	5,306	0	0
Unrealized foreign currency transaction (gains) losses, net	(573)	562	(1,217)
Non-cash stock compensation expense	14,981	11,017	8,336
Loss on disposal of fixed assets	69	299	293
Deferred tax provision (benefit)	30,376	(53,246)	(43,592)
Excess tax benefit from share-based compensation arrangements	(1,558)	(9,393)	292
Change in contingent consideration obligation	(1,460)	(4,956)	1,720
Changes in operating assets and liabilities:
Accrued interest receivable	26	905	(364)
Accounts receivable	(11,120)	(28,086)	(16,627)
Inventory	(31,152)	(19,794)	701
Prepaid expenses and other current assets	1,516	(6,763)	5,031
Accounts payable	18,903	(2,203)	165
Accrued expenses	(40,160)	71,608	(736)
Deferred revenue	1,685	125	(616)
Other liabilities	(265)	171	62
Net cash provided by operating activities	46,346	96,375	67,467
Cash flows from investing activities:
Purchases of available for sale securities	(65,354)	(33,583)	(128,240)
Proceeds from maturities and sales of available for sale securities	38,881	126,713	108,640
Purchases of fixed assets	(1,005)	(1,269)	(340)
Acquisition of intangible assets	(36,678)	(7,000)	0
Other investments	(2,500)	(7,500)	0
Adjustment to goodwill	0	0	263
Decrease in restricted cash	3,148	1,049	1,278
Net cash (used in) provided by investing activities	(63,508)	78,410	(18,399)
Cash flows from financing activities:
Proceeds from issuances of common stock, net	22,935	6,725	3,361
Purchase of treasury stock	(50,000)	0	0
Proceeds from the issuance of convertible senior notes	275,000	0	0
Proceeds from issuance of warrants	38,425	0	0
Purchase of convertible note hedge	(58,223)	0	0
Debt issuance costs	(8,774)	0	0
Excess tax benefit from share-based compensation arrangements	1,558	9,393	0
Net cash provided by financing activities	220,921	16,118	3,361
Effect of exchange rate changes on cash	305	(1,885)	1,710
Increase in cash and cash equivalents	204,064	189,018	54,139
Cash and cash equivalents at beginning of period	315,382	126,364
Cash and cash equivalents at end of period	519,446	315,382	126,364
Supplemental disclosure of cash flow information:
Taxes paid	1,709	6,850	1,699
Interest paid	$ 1,786	$ 0	$ 0