CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Operating activities:
Net loss	$ (62,917)	$ (16,717)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation	1,841	1,571
Amortization of patents	376	312
Amortization of licenses	1	469
Amortization of premium on investments, net	2,039	1,749
Amortization of debt issuance costs	298	275
Amortization of long-term financing liability for leased facility	1,672	1,662
Stock-based compensation expense	20,103	13,305
Non-cash losses related to patents, licensing and property, plant and equipment	396	93
Tax benefit from other unrealized gains on securities	0	(798)
Changes in operating assets and liabilities:
Contracts receivable	(5,124)	(23,031)
Inventories	379	(549)
Other current and long-term assets	(2,747)	(2,451)
Accounts payable	(11,417)	(2,695)
Accrued compensation	(9,728)	(6,891)
Deferred rent	48	62
Accrued liabilities	(1,934)	(6,704)
Deferred contract revenue	(14,849)	(7,841)
Net cash provided by (used in) operating activities	(75,768)	(42,826)
Investing activities:
Purchases of short-term investments	(41,366)	(40,213)
Proceeds from the sale of short-term investments	81,805	78,460
Purchases of property, plant and equipment	(628)	(878)
Acquisition of licenses and other assets, net	(382)	(719)
Net cash used in investing activities	39,429	36,650
Financing activities:
Proceeds from equity awards	2,736	14,116
Principal payments on debt and capital lease obligations	(1,857)	(2,590)
Net cash provided by financing activities	879	11,526
Net decrease in cash and cash equivalents	(35,460)	5,350
Cash and cash equivalents at beginning of period	128,797	142,998
Cash and cash equivalents at end of period	93,337	148,348
Supplemental disclosures of cash flow information:
Interest paid	31	37
Supplemental disclosures of non-cash investing and financing activities:
Amounts accrued for capital and patent expenditures	2,524	1,198
2 3/4 Percent Convertible Senior Notes [Member]
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Amortization of convertible notes discount	620	565
1 Percent Convertible Senior Notes [Member]
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Amortization of convertible notes discount	$ 5,175	$ 4,788