CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cash flows from operating activities:
Net income	$ 636,056	$ 338,126	$ 413,738
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation and amortization	74,909	52,686	41,204
Non-cash compensation expense	459,049	321,750	215,377
Loss on Extinguishment of Debt	18,861	33,469	0
Other non-cash charges and expenses, net	33,701	44,102	46,751
Increase (Decrease) in Deferred Income Taxes	(121,623)	(53,276)	62,195
Changes in assets and liabilites
Increase in Sanofi, Bayer HealthCare, and trade accounts receivable	(491,421)	(34,927)	(245,472)
Increase in Inventories	(111,825)	(56,947)	(47,956)
(Increase) decrease in prepaid expenses and other assets	(79,476)	(45,327)	7,571
Increase (decrease) in deferred revenue	608,892	(8,403)	(41,496)
Increase in accounts payable, accrued expenses and other liabilities	303,657	161,182	136,684
Total adjustments	694,724	414,309	174,858
Net cash provided by operating activities	1,330,780	752,435	588,596
Cash flows from investing activities:
Purchases of marketable securities	(557,105)	(564,188)	(577,278)
Sales or maturities of marketable securities	327,437	476,417	378,146
Capital expenditures	(677,933)	(333,006)	(156,323)
Net cash used in by investing activities	(907,601)	(420,777)	(355,455)
Cash flows from financing activities:
Proceeds from (Repayments of) Long-term Debt and Capital Securities	26,020	(1,095)	(2,024)
Repayments of convertible senior debt	(166,467)	(220,639)	0
Payments in connection with reduction of outstanding warrants	(573,487)	(294,552)	0
Proceeds from issuance of Common Stock	206,358	126,045	57,393
Payments in connection with Common Stock tendered for employee tax obligations	(160,537)	(267,584)	(195,087)
Excess tax benefit from stock-based compensation	405,317	439,278	211,909
Net cash (used in) provided by financing activities	(262,796)	(218,547)	72,191
Net increase in cash and cash equivalents	160,383	113,111	305,332
Cash and cash equivalents at beginning of period	648,719	535,608	230,276
Cash and cash equivalents at end of period	809,102	648,719	535,608
Cash paid for interest (net of amounts capitalized)	10,582	20,348	23,197
Cash paid for income taxes	276,092	59,847	$ 1,057
Warrant
Cash flows from financing activities:
Payments in connection with reduction of outstanding warrants	$ (399,500)	$ (294,600)