Annual report pursuant to Section 13 and 15(d)

Quarterly Financial Data - Schedule of Quarterly Financial Information (Detail)

v2.4.1.9
Quarterly Financial Data - Schedule of Quarterly Financial Information (Detail) (USD $)
In Thousands, except Per Share data, unless otherwise specified
3 Months Ended 12 Months Ended
Dec. 31, 2014
Sep. 30, 2014
Jun. 30, 2014
Mar. 31, 2014
Dec. 31, 2013
Sep. 30, 2013
Jun. 30, 2013
Mar. 31, 2013
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Quarterly Financial Information Disclosure [Abstract]                      
Revenue $ 3,681us-gaap_ContractsRevenue $ 3,680us-gaap_ContractsRevenue $ 3,680us-gaap_ContractsRevenue $ 3,681us-gaap_ContractsRevenue $ 3,212us-gaap_ContractsRevenue $ 3,181us-gaap_ContractsRevenue $ 3,180us-gaap_ContractsRevenue $ 2,922us-gaap_ContractsRevenue $ 14,722us-gaap_ContractsRevenue $ 12,495us-gaap_ContractsRevenue $ 5,867us-gaap_ContractsRevenue
Net income (loss) $ (5,964)us-gaap_NetIncomeLoss $ (7,745)us-gaap_NetIncomeLoss $ (766)us-gaap_NetIncomeLoss $ (7,109)us-gaap_NetIncomeLoss $ (7,589)us-gaap_NetIncomeLoss $ 1,176us-gaap_NetIncomeLoss $ (12,788)us-gaap_NetIncomeLoss $ (9,214)us-gaap_NetIncomeLoss $ (21,584)us-gaap_NetIncomeLoss $ (28,415)us-gaap_NetIncomeLoss $ (71,135)us-gaap_NetIncomeLoss
Net income (loss) per common share                      
Basic $ (0.09)us-gaap_EarningsPerShareBasic $ (0.13)us-gaap_EarningsPerShareBasic $ (0.01)us-gaap_EarningsPerShareBasic $ (0.12)us-gaap_EarningsPerShareBasic $ (0.13)us-gaap_EarningsPerShareBasic $ 0.02us-gaap_EarningsPerShareBasic $ (0.22)us-gaap_EarningsPerShareBasic $ (0.16)us-gaap_EarningsPerShareBasic $ (0.36)us-gaap_EarningsPerShareBasic $ (0.49)us-gaap_EarningsPerShareBasic $ (1.31)us-gaap_EarningsPerShareBasic
Diluted $ (0.12)us-gaap_EarningsPerShareDiluted $ (0.15)us-gaap_EarningsPerShareDiluted $ (0.12)us-gaap_EarningsPerShareDiluted $ (0.14)us-gaap_EarningsPerShareDiluted $ (0.13)us-gaap_EarningsPerShareDiluted $ (0.08)us-gaap_EarningsPerShareDiluted $ (0.22)us-gaap_EarningsPerShareDiluted $ (0.16)us-gaap_EarningsPerShareDiluted $ (0.49)us-gaap_EarningsPerShareDiluted $ (0.49)us-gaap_EarningsPerShareDiluted $ (1.31)us-gaap_EarningsPerShareDiluted