CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Cash flows from operating activities:
Net income	$ 65,443	$ 98,874
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	11,530	9,407
Non-cash compensation expense	81,408	53,030
Non-cash interest expense	5,916	5,781
Other non-cash charges and expenses, net	3,761	7,174
Deferred taxes	(8,522)	39,525
Changes in assets and liabilites
Increase in Sanofi, Bayer HealthCare, and trade accounts receivable	(92,529)	(117,782)
Increase in Inventories	(15,550)	(17,581)
Increase in prepaid expenses and other assets	(20,898)	(17,815)
Increase (decrease) in deferred revenue	37,107	(6,470)
(Decrease) increase in accounts payable, accrued expenses and other liabilities	(14,139)	32,105
Total adjustments	(11,916)	(12,626)
Net cash provided by operating activities	53,527	86,248
Cash flows from investing activities:
Purchases of marketable securities	(253,878)	(181,236)
Sales or maturities of marketable securities	82,469	54,754
Capital expenditures	(64,822)	(21,203)
Net cash used in investing activities	(236,231)	(147,685)
Cash flows from financing activities:
Payments in connection with facility and capital lease obligations	(262)	(649)
Proceeds from issuance of Common Stock	55,042	12,964
Payments in connection with Common Stock tendered for employee tax obligations	(63,086)	(3,085)
Excess tax benefit from stock-based compensation	117,260	2,293
Net cash provided by financing activities	108,954	11,523
Net decrease in cash and cash equivalents	(73,750)	(49,914)
Cash and cash equivalents at beginning of period	535,608	230,276
Cash and cash equivalents at end of period	$ 461,858	$ 180,362