CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Cash flows from operating activities:
Net income	$ 1,624,047	$ 1,024,992
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	105,441	110,960
Non-cash compensation expense	300,652	380,144
Other non-cash items, net	(82,694)	44,016
Deferred taxes	(33,521)	(108,242)
Changes in assets and liabilities:
Increase in Sanofi, Bayer, and trade accounts receivable	(228,605)	(359,829)
Increase in inventories	(281,624)	(235,645)
Increase in prepaid expenses and other assets	(87,817)	(28,209)
Increase (decrease) in deferred revenue	(29,462)	(59,116)
Increase (decrease) in accounts payable, accrued expenses, and other liabilities	179,852	(28,908)
Total adjustments	(157,778)	(284,829)
Net cash provided by operating activities	1,466,269	740,163
Cash flows from investing activities:
Purchases of marketable and other securities	(1,533,558)	(883,748)
Sales or maturities of marketable securities	644,103	379,275
Capital expenditures	(297,638)	(164,963)
Other	(10,000)	0
Net cash used in investing activities	(1,197,093)	(669,436)
Cash flows from financing activities:
Proceeds in connection with capital and facility lease obligations	0	57,000
Payments in connection with capital and facility lease obligations	0	(19,925)
Proceeds from issuance of Common Stock	87,408	226,892
Payments in connection with Common Stock tendered for employee tax obligations	(77,096)	(77,832)
Repurchases of Common Stock	(4,378)	0
Net cash provided by financing activities	5,934	186,135
Net increase in cash, cash equivalents, and restricted cash	275,110	256,862
Cash, cash equivalents, and restricted cash at beginning of period	825,233	547,703
Cash, cash equivalents, and restricted cash at end of period	$ 1,100,343	$ 804,565