CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Cash flows from operating activities:
Net income	$ 636,675	$ 377,603
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	73,241	48,006
Non-cash compensation expense	255,047	273,941
Other non-cash charges and expenses, net	37,631	7,795
Deferred taxes	(57,737)	(162,652)
Changes in assets and liabilites
Increase in Sanofi, Bayer, and trade accounts receivable	(232,927)	(284,178)
Increase in Inventories	(151,544)	(72,888)
(Increase) decrease in prepaid expenses and other assets	(77,168)	57,086
Increase in deferred revenue	(10,655)	65,850
Increase in accounts payable, accrued expenses and other liabilities	(147,232)	133,925
Total adjustments	(311,344)	66,885
Net cash provided by operating activities	325,331	444,488
Cash flows from investing activities:
Purchases of marketable securities	(477,408)	(228,942)
Sales or maturities of marketable securities	272,166	102,177
Capital expenditures	(105,310)	(242,930)
Net cash used in investing activities	(310,552)	(369,695)
Cash flows from financing activities:
Proceeds in connection with capital and facility lease obligations	57,000	0
Repayments of Long-term Debt, Long-term Capital Lease Obligations, and Capital Securities	19,925	1,213
Repayments of convertible senior notes	0	(12,650)
Payments in connection with deduction of outstanding warrants	0	(242,117)
Proceeds from issuance of Common Stock	188,693	63,606
Payments in connection with Common Stock tendered for employee tax obligations	(31,437)	(45,013)
Net cash provided by (used in) financing activities	194,331	(237,387)
Net increase (decrease) in cash and cash equivalents	209,110	(162,594)
Cash and cash equivalents at beginning of period	535,203	809,102
Cash and cash equivalents at end of period	$ 744,313	$ 646,508