v2.4.1.9
Selected Quarterly Financial Data - Summary of Selected Quarterly Financial Data (Detail) (USD $)
In Thousands, except 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]                      
Total revenue $ 7,952us-gaap_Revenues $ 6,654us-gaap_Revenues $ 6,776us-gaap_Revenues $ 5,924us-gaap_Revenues $ 5,855us-gaap_Revenues $ 5,805us-gaap_Revenues $ 5,457us-gaap_Revenues $ 4,981us-gaap_Revenues $ 27,306us-gaap_Revenues $ 22,098us-gaap_Revenues $ 20,451us-gaap_Revenues
Net income (loss) $ (5)us-gaap_NetIncomeLoss $ 1,213us-gaap_NetIncomeLoss $ 877us-gaap_NetIncomeLoss $ (1,304)us-gaap_NetIncomeLoss $ (562)us-gaap_NetIncomeLoss $ (830)us-gaap_NetIncomeLoss $ (802)us-gaap_NetIncomeLoss $ (1,348)us-gaap_NetIncomeLoss $ 781us-gaap_NetIncomeLoss $ (3,542)us-gaap_NetIncomeLoss $ (5,059)us-gaap_NetIncomeLoss
Net income (loss) per common share, basic $ 0.00us-gaap_EarningsPerShareBasic $ 0.13us-gaap_EarningsPerShareBasic $ 0.87us-gaap_EarningsPerShareBasic $ (1.29)us-gaap_EarningsPerShareBasic         $ 0.13us-gaap_EarningsPerShareBasic $ (3.50)us-gaap_EarningsPerShareBasic $ (5.01)us-gaap_EarningsPerShareBasic
Net loss per common share, basic and diluted         $ (0.56)us-gaap_EarningsPerShareBasicAndDiluted $ (0.82)us-gaap_EarningsPerShareBasicAndDiluted $ (0.79)us-gaap_EarningsPerShareBasicAndDiluted $ (1.33)us-gaap_EarningsPerShareBasicAndDiluted      
Net income (loss) per common share, diluted $ 0.00us-gaap_EarningsPerShareDiluted $ 0.12us-gaap_EarningsPerShareDiluted $ 0.13us-gaap_EarningsPerShareDiluted $ (1.29)us-gaap_EarningsPerShareDiluted         $ 0.10us-gaap_EarningsPerShareDiluted $ (3.50)us-gaap_EarningsPerShareDiluted $ (5.01)us-gaap_EarningsPerShareDiluted
Shares used in calculation of net loss per share, basic and diluted         1,011,136us-gaap_WeightedAverageNumberOfShareOutstandingBasicAndDiluted 1,011,136us-gaap_WeightedAverageNumberOfShareOutstandingBasicAndDiluted 1,011,123us-gaap_WeightedAverageNumberOfShareOutstandingBasicAndDiluted 1,010,684us-gaap_WeightedAverageNumberOfShareOutstandingBasicAndDiluted      
Shares used in calculation of net income (loss) per share, basic 11,802,241us-gaap_WeightedAverageNumberOfSharesOutstandingBasic 9,279,649us-gaap_WeightedAverageNumberOfSharesOutstandingBasic 1,013,128us-gaap_WeightedAverageNumberOfSharesOutstandingBasic 1,011,980us-gaap_WeightedAverageNumberOfSharesOutstandingBasic         5,815,928us-gaap_WeightedAverageNumberOfSharesOutstandingBasic 1,010,795us-gaap_WeightedAverageNumberOfSharesOutstandingBasic 1,009,236us-gaap_WeightedAverageNumberOfSharesOutstandingBasic
Shares used in calculation of net income (loss) per share, diluted 11,802,241us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding 11,219,377us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding 6,939,568us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding 1,011,980us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding         9,283,001us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding 1,010,795us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding 1,009,236us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding