Condensed Balance Sheets (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Current assets
Cash	$ 54,649	$ 77,975
Accounts receivable	2,966us-gaap_AccountsReceivableNetCurrent	59us-gaap_AccountsReceivableNetCurrent
Prepaid expenses and other current assets	134	60
Total current assets	57,749us-gaap_AssetsCurrent	78,094us-gaap_AssetsCurrent
Property and equipment
Computers, software and equipment	4,270xncr_ComputersSoftwareAndEquipmentGross	3,514xncr_ComputersSoftwareAndEquipmentGross
Furniture and fixtures	97us-gaap_FurnitureAndFixturesGross	89us-gaap_FurnitureAndFixturesGross
Leasehold improvements	3,086us-gaap_LeaseholdImprovementsGross	3,081us-gaap_LeaseholdImprovementsGross
Less accumulated depreciation and amortization	(6,554)	(6,377)
Property and equipment, net	899us-gaap_PropertyPlantAndEquipmentNet	307us-gaap_PropertyPlantAndEquipmentNet
Other assets
Patents, licenses, and other intangible assets, net	9,116	8,814
Other assets	59	100
Total other assets	9,175us-gaap_OtherAssetsNoncurrent	8,914us-gaap_OtherAssetsNoncurrent
Total assets	67,823us-gaap_Assets	87,315us-gaap_Assets
Current liabilities
Accounts payable	1,691us-gaap_AccountsPayableCurrent	2,633us-gaap_AccountsPayableCurrent
Accrued expenses	2,251us-gaap_AccruedLiabilitiesCurrent	1,393us-gaap_AccruedLiabilitiesCurrent
Current portion of deferred revenue	2,254us-gaap_DeferredRevenueCurrent	3,444us-gaap_DeferredRevenueCurrent
Current portion of capital lease obligations		9us-gaap_CapitalLeaseObligationsCurrent
Total current liabilities	6,196us-gaap_LiabilitiesCurrent	7,479us-gaap_LiabilitiesCurrent
Deferred revenue, less current portion	2,337us-gaap_DeferredRevenueNoncurrent	6,302us-gaap_DeferredRevenueNoncurrent
Capital lease obligations, less current portion		1
Total liabilities	8,533us-gaap_Liabilities	13,782us-gaap_Liabilities
Commitments and contingencies
Stockholders' equity
Common stock, $0.01 par value: 200,000,000 authorized shares; 31,434,272 issued and outstanding shares at December 31, 2014 and 31,354,467 issued and outstanding at December 31, 2013	314us-gaap_CommonStockValue	314us-gaap_CommonStockValue
Additional paid-in capital	302,969us-gaap_AdditionalPaidInCapital	300,790us-gaap_AdditionalPaidInCapital
Accumulated deficit	(243,993)	(227,571)
Total stockholders' equity	59,290us-gaap_StockholdersEquity	73,533us-gaap_StockholdersEquity
Total liabilities and stockholders' equity	$ 67,823	$ 87,315

Carrying value as of the balance sheet date of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19

-Subparagraph a

-Article 5

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.19(a))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682