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	$ 15,260	$ 51,170	$ 127,877
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	32,238	7,270	6,231
Amortization of net premiums and discounts on available for sale securities	209	734	2,021
Amortization of long term debt financing costs	1,179	598	0
Amortization of debt discount	9,978	5,306	0
Unrealized foreign currency transaction (gains) losses, net	143	(573)	562
Non-cash stock compensation expense	23,078	14,981	11,017
Loss on disposal of fixed assets	39	69	299
Deferred tax provision (benefit)	(10,272)	30,376	(53,246)
Excess tax benefit from share-based compensation arrangements	(7,675)	(1,558)	(9,393)
Change in contingent consideration obligation	16,942	(1,460)	(4,956)
Changes in operating assets and liabilities:
Accrued interest receivable	347	26	905
Accounts receivable	(15,017)	(11,120)	(28,086)
Inventory	(10,130)	(31,152)	(19,794)
Prepaid expenses and other current assets	39	1,516	(6,763)
Accounts payable	(1,319)	18,903	(2,203)
Accrued expenses	31,192	(40,160)	71,608
Deferred revenue	3,854	1,685	125
Other liabilities	1,335	(265)	171
Net cash provided by operating activities	91,420	46,346	96,375
Cash flows from investing activities:
Purchases of available for sale securities	0	(65,354)	(33,583)
Proceeds from maturities and sales of available for sale securities	50,656	38,881	126,713
Purchases of fixed assets	(13,574)	(1,005)	(1,269)
Acquisition of intangible assets	0	(36,678)	(7,000)
Other investments	1,125	(2,500)	(7,500)
Acquisition of businesses, net of cash acquired	542,579	0	0
Decrease in restricted cash	11	3,148	1,049
Other investing activities	0	0	0
Net cash (used in) provided by investing activities	(504,361)	(63,508)	78,410
Cash flows from financing activities:
Proceeds from issuances of common stock	74,212	22,935	6,725
Proceeds from equity offering, net	189,600	0
Purchase of treasury stock		(50,000)	0
Proceeds from the issuance of convertible senior notes		275,000	0
Proceeds from issuance of warrants		38,425	0
Purchase of convertible note hedge		(58,223)	0
Debt issuance costs	0	(8,774)	0
Excess tax benefit from share-based compensation arrangements	7,675	1,558	9,393
Net cash provided by financing activities	271,487	220,921	16,118
Effect of exchange rate changes on cash	(1,265)	305	(1,885)
(Decrease) increase in cash and cash equivalents	(142,719)	204,064	189,018
Cash and cash equivalents at beginning of period	519,446	315,382	126,364
Cash and cash equivalents at end of period	376,727	519,446	315,382
Supplemental disclosure of cash flow information:
Taxes paid	9,137	1,709	6,850
Interest paid	$ 4,374	$ 1,786	$ 0