Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash flows from operating activities:
Net income (loss)	$ 91,635	$ (84,031)	$ (588,181)
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Stock-based compensation expense	290,736	237,705	231,025
Depreciation expense	61,397	61,398	62,343
Write-downs of inventories to net realizable value	15,292	0	0
Deferred income taxes	(120,513)	16,961	3,283
Impairment of property and equipment	1,951	0	2,516
Intangible asset impairment charge	255,340	0	0
Acquired in-process research and development	160,000	0	0
Deconsolidation of VIE	76,644	0	0
Other non-cash items, net	(2,804)	6,140	9,532
Changes in operating assets and liabilities:
Accounts receivable, net	(71,759)	(39,095)	(110,098)
Inventories	(44,984)	(16,450)	(23,146)
Prepaid expenses and other assets	(111,063)	(2,631)	(4,009)
Accounts payable	8,753	(11,745)	(1,709)
Accrued expenses and other liabilities	246,217	88,649	102,746
Accrued restructuring expense	(5,987)	(7,426)	(30,492)
Deferred revenues	(5,913)	(13,372)	(19,242)
Net cash provided by provided by (used in) operating activities	844,942	236,103	(365,432)
Cash flows from investing activities:
Maturities of marketable securities	369,214	757,562	1,067,443
Purchases of marketable securities	(532,581)	(616,625)	(633,041)
Expenditures for property and equipment	(99,421)	(56,563)	(45,302)
Purchase of in-process research and development	(160,000)	0	0
Investment in note receivable	0	(20,000)	(30,000)
Investment in equity securities	0	(13,075)	0
(Decrease) increase in restricted cash and cash equivalents (VIE)	(15,329)	31,148	11,685
Increase (decrease) in restricted cash and cash equivalents and other assets	436	22,022	(21,929)
Payment for acquisition of variable interest entity	0	0	(80,000)
Net cash (used in) provided by investing activities	(437,681)	104,469	268,856
Cash flows from financing activities:
Issuances of common stock under benefit plans	344,840	68,230	185,592
Payments on revolving credit facility	(300,000)	0	0
Advance from collaborator	12,500	75,000	0
Payments on construction financing lease obligation	(541)	(432)	(381)
Proceeds related to construction financing lease obligation	27,182	0	0
Proceeds from capital lease financing	7,484	11,208	23,662
Payments on capital lease obligations	(18,795)	(17,597)	(19,954)
Repayments of advanced funding	(4,266)	0	0
Payments on senior secured term loan	0	(75,000)	0
Proceeds from revolving credit facility	0	74,965	0
Payments of debt issuance costs	0	(3,103)	0
Net cash provided by financing activities	68,404	133,271	188,919
Effect of changes in exchange rates on cash	5,802	(4,666)	(2,834)
Net increase in cash and cash equivalents	481,467	469,177	89,509
Cash and cash equivalents—beginning of period	1,183,945	714,768	625,259
Cash and cash equivalents—end of period	1,665,412	1,183,945	714,768
Supplemental disclosure of cash flow information:
Cash paid for interest	68,696	83,656	85,613
Cash paid for (received from) income taxes	6,414	(2,579)	1,806
Non-cash investing and financing activities:
Capitalization of costs related to construction financing lease obligation	40,855	14,238	0
Issuances of common stock from employee benefit plans receivable	844	68	361
Proceeds from revolving credit facility directly paid to settle all outstanding obligations under the term loan	$ 0	$ 225,000	$ 0