Annual report pursuant to Section 13 and 15(d)

Warrants - Additional Information (Details)

v2.4.1.9
Warrants - Additional Information (Details) (USD $)
In Thousands, unless otherwise specified
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Equity [Abstract]      
Fair value of preferred warrant liability $ 0ingn_PreferredStockWarrantLiability $ 260ingn_PreferredStockWarrantLiability  
Change in fair value of preferred warrants liability $ 36us-gaap_FairValueAdjustmentOfWarrants $ (262)us-gaap_FairValueAdjustmentOfWarrants $ 148us-gaap_FairValueAdjustmentOfWarrants