CONDENSED CONSOLIDATED STATEMENTS OF CASHFLOWS (USD $)	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
Cash flows from operating activities:
Net loss	$ (156,851,000)	$ (199,995,000)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation, amortization and impairment charges	6,079,000	2,847,000
Stock-based compensation	24,583,000	28,559,000
Deferred executive compensation expense	119,000	803,000
Increase (decrease) from:
Accounts receivable	(5,957,000)	(7,024,000)
Inventory	1,549,000	(571,000)
Other current assets	(1,661,000)	(6,570,000)
Other assets	103,000	(7,538,000)
Accounts payable	(166,000)	7,101,000
Accrued compensation and benefits	1,649,000	1,216,000
Accrued product development expenses	(2,947,000)	3,261,000
Other accrued expenses	1,154,000	1,722,000
Other liabilities	1,602,000	5,085,000
Deferred revenue	1,445,000	4,744,000
Deferred executive compensation paid	(2,631,000)	(3,953,000)
Net cash used in operating activities	(131,930,000)	(170,313,000)
Cash flows from investing activities:
Proceeds from maturities of marketable securities		35,000,000
Change in restricted cash		(6,133,000)
Investment in property and equipment	(2,475,000)	(5,624,000)
Net cash provided by (used in) investing activities	(2,475,000)	23,243,000
Cash flows from financing activities:
Proceeds from issuance of convertible debt	192,921,000
Proceeds from the issuance of warrants	27,580,000
Purchase of convertible bond hedges	(43,220,000)
Repayment of long-term borrowings	(9,100,000)	(1,575,000)
Principal payments under capital lease obligation		(15,000)
Proceeds from issuance of common stock, net of issuance costs		310,037,000
Proceeds under lease financing obligation		1,294,000
Proceeds from issuance of common stock pursuant to stock option and purchase plans	3,059,000	5,632,000
Payment of tax withholding obligations related to stock compensation	(716,000)	(3,216,000)
Net cash provided by financing activities	170,524,000	312,157,000
Effect of exchange rates on cash	153,000	(30,000)
Net increase in cash and cash equivalents	36,272,000	165,057,000
Cash and cash equivalents, beginning of period	237,179,000	119,379,000
Cash and cash equivalents, end of period	273,451,000	284,436,000
Supplemental non-cash investing and financing disclosure:
Capitalization of construction-in-progress related to facility lease obligation	71,818,000	66,728,000
Investment in property and equipment included in accounts payable or accruals	$ 187,000	$ 1,217,000