Notes Payable - Schedule of Annual Repayment Requirements for Credit Facility (Detail) - 2014 Credit Facility [Member]
$ in Thousands
12 Months Ended
Dec. 31, 2015
USD ($)
Line of Credit Facility [Line Items]  
Credit Facility, Principal $ 15,600
Credit Facility, Interest and Final Payment 3,897
Credit Facility, Total 19,497
2016 [Member]  
Line of Credit Facility [Line Items]  
Credit Facility, Interest and Final Payment 1,301
Credit Facility, Total 1,301
2017 [Member]  
Line of Credit Facility [Line Items]  
Credit Facility, Principal 5,200
Credit Facility, Interest and Final Payment 1,105
Credit Facility, Total 6,305
2018 [Member]  
Line of Credit Facility [Line Items]  
Credit Facility, Principal 5,200
Credit Facility, Interest and Final Payment 670
Credit Facility, Total 5,870
2019 [Member]  
Line of Credit Facility [Line Items]  
Credit Facility, Principal 5,200
Credit Facility, Interest and Final Payment 821
Credit Facility, Total $ 6,021