Condensed Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Operating activities
Net loss	$ (88,531)	$ (84,277)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation	7,962	9,224
Depreciation and amortization	11,388	7,826
Noncash restructuring costs	2,383	0
Other non-cash items	833	(1,486)
Changes in operating assets and liabilities:
Accounts receivable	(832)	(1,134)
Inventories	(9,882)	(3,243)
Prepaid expenses and other assets	(1,475)	391
Accounts payable and accrued expenses	1,309	5,063
Other liabilities	1,812	2,106
Net cash used in operating activities	(75,033)	(65,530)
Investing activities
Purchases of property, equipment and leasehold improvements	(11,720)	(12,370)
Purchases of marketable securities	(52,823)	(12,751)
Maturities of marketable securities	59,076	54,574
Net cash paid for other assets	(483)	(1,396)
Net cash provided by (used in) investing activities	(5,950)	28,057
Financing activities
Payments on term loan and capital lease obligations	(5,527)	(639)
Borrowings on term loan	0	5,000
Proceeds from convertible debt, net of issuance costs	0	124,814
Proceeds from stock offering, net of issuance costs	0	58,161
Net proceeds from exercise of stock options and ESPP purchases	1,372	1,118
Net cash provided by (used in) financing activities	(4,155)	188,454
Effect of exchange rate changes on cash and cash equivalents	88	(18)
Net increase (decrease) in cash and cash equivalents	(85,050)	150,963
Cash and cash equivalents at beginning of period	123,802	28,926
Cash and cash equivalents at end of period	38,752	179,889
Supplemental non-cash investing and financing activity:
Building and improvements acquired through financing obligation	$ 0	$ 1,872