CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenues:
Net product sales	$ 3,718,463	$ 3,338,390	$ 2,689,478
Sanofi collaboration revenue	877,193	658,665	758,873
Bayer collaboration revenue	938,052	744,270	580,488
Other revenue	338,519	119,102	74,889
Total revenues	5,872,227	4,860,427	4,103,728
Expenses:
Research and development	2,075,142	2,052,295	1,620,577
Selling, general, and administrative	1,320,433	1,177,697	838,526
Cost of goods sold	202,507	194,624	241,702
Cost of collaboration and contract manufacturing	194,554	105,070	151,007
Total expenses	3,792,636	3,529,686	2,851,812
Income from operations	2,079,591	1,330,741	1,251,916
Other income (expense):
Other income (expense), net	24,039	6,269	(12,578)
Interest expense, net	(25,119)	(7,195)	(14,241)
Total other income (expense)	(1,080)	(926)	(26,819)
Income before income taxes	2,078,511	1,329,815	1,225,097
Income tax expense	(880,000)	(434,293)	(589,041)
Net income	$ 1,198,511	$ 895,522	$ 636,056
Net income per share - basic	$ 11.27	$ 8.55	$ 6.17
Net income per share - diluted	$ 10.34	$ 7.70	$ 5.52
Weighted average shares outstanding - basic	106,338	104,719	103,061
Weighted average shares outstanding - diluted	115,954	116,367	115,230
Statements of Comprehensive Income
Net income	$ 1,198,511	$ 895,522	$ 636,056
Other comprehensive income (loss), net of tax:
Unrealized (loss) gain on marketable securities	12,715	(21,412)	(43,679)
Unrealized gain on cash flow hedges	765	0	0
Comprehensive income	$ 1,211,991	$ 874,110	$ 592,377