CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016		Sep. 30, 2015
Cash flows from operating activities:
Net income (loss)	$ 95,349		$ (48,645)
Adjustments to reconcile net income (loss) to net cash used in operating activities:
Depreciation and amortization	40,859		34,279
Stock-based compensation	68,598		52,775
Other, net	325		(1,830)
Unrealized (gain) loss on long term investment	(20,497)		4,115
Excess tax benefit from stock-based compensation			(2,094)
Change in fair value of acquisition-related contingent consideration	10,283
Changes in operating assets and liabilities:
Accounts receivable	(6,712)		(29,033)
Prepaid expenses and other assets	(13,323)		(1,918)
Inventory	4,439		(830)
Accounts payable	25,683		2,904
Accrued and other liabilities	15,018		16,469
Deferred revenue - collaborative agreements	(9,644)		(9,665)
Net cash provided by operating activities	210,378		16,527
Cash flows from investing activities:
Acquisition of business, net of cash acquired	(142,965)
Long term investment			(39,829)
Capital expenditures	(104,405)		(19,107)
Purchases of marketable securities	(26,921)		(94,376)
Sale and maturities of marketable securities	77,815		52,831
Net cash (used in) investing activities	(196,476)		(100,481)
Cash flows from financing activities:
Restricted investments, net	13,976		(128)
Proceeds from issuance of common stock under stock plans	32,468		76,871
Direct financing arrangements repayments	(445)		(1,379)
Excess tax benefit from stock-based compensation			2,094
Payment of contingent consideration	(1,226)
Net cash provided by financing activities	44,773		77,458
Effect of exchange rates on cash and cash equivalents	(15)
Net increase (decrease) in cash and cash equivalents	58,660		(6,496)
Cash and cash equivalents at beginning of period	521,439	[1]	452,297
Cash and cash equivalents at end of period	580,099		445,801
Supplemental Schedule of Cash Flow Information
Interest paid	3,892		7,698
Incomes taxes paid	717		86
4.75% Convertible Senior Notes due 2015
Supplemental Schedule of Cash Flow Information
Reclassification to common stock and additional paid in capital in connection with conversions or exchange of convertible senior notes			$ 88,962
0.375% Convertible Senior Notes due 2018
Supplemental Schedule of Cash Flow Information
Reclassification to common stock and additional paid in capital in connection with conversions or exchange of convertible senior notes	5
1.25% Convertible Senior Notes due 2020
Supplemental Schedule of Cash Flow Information
Reclassification to common stock and additional paid in capital in connection with conversions or exchange of convertible senior notes	$ 4

[1] The condensed consolidated balance sheet at December 31, 2015 has been derived from the audited financial statements at that date.