Quarterly report pursuant to Section 13 or 15(d)

Stockholders' Equity - Additional Information (Details)

v3.19.1
Stockholders' Equity - Additional Information (Details) - USD ($)
6 Months Ended 12 Months Ended
Mar. 31, 2019
Sep. 30, 2018
Dec. 31, 2018
Mar. 31, 2018
Dec. 31, 2017
Dec. 12, 2017
Oct. 08, 2017
Class Of Stock [Line Items]              
Common stock, shares authorized 100,000,000 100,000,000          
Common stock, shares issued 4,193,926 4,152,789          
Common stock, shares outstanding 4,193,926 4,152,789          
Preferred stock, shares authorized 1,000,000 1,000,000          
Preferred stock, shares issued 0 0          
Preferred stock, shares outstanding 0 0          
Rights              
Class Of Stock [Line Items]              
Number of shares of common stock each holder receive           0.10  
Warrants or rights outstanding 14,873,256 14,873,256          
Number of fractional shares issued upon conversion of rights 0            
Additional consideration required to be paid by holder of right to receive additional shares $ 0            
Funds and distributions to be received by rights holders upon liquidation of funds held in trust account 0            
Contractual penalties for failure to deliver securities to the rights holders $ 0            
Minimum | Rights              
Class Of Stock [Line Items]              
Period allotted to complete the business combination 18 months            
Maximum | Rights              
Class Of Stock [Line Items]              
Period allotted to complete the business combination 24 months            
Common Stock              
Class Of Stock [Line Items]              
Common stock, shares authorized 100,000,000            
Common stock, voting rights per share one            
Common stock, shares issued 4,193,926 4,152,789          
Common stock, shares outstanding 4,193,926 4,152,789 4,169,199 4,103,645 4,105,843   0
Shares subject to possible redemption   14,309,217   14,268,080      
Number of shares of common stock each holder receive 0.10            
Common Stock | Independent Directors              
Class Of Stock [Line Items]              
Common stock issued in consideration of future services, shares 60,000 60,000          
Preferred Stock              
Class Of Stock [Line Items]              
Preferred stock, shares authorized 1,000,000            
Preferred stock, shares issued 0            
Preferred stock, shares outstanding 0            
Warrants              
Class Of Stock [Line Items]              
Exercise price of warrants $ 11.50         $ 11.50  
Number of shares of common stock each holder receive 4         0.75  
Warrant agreement date Dec. 12, 2017            
Number of fractional shares issued upon exercise of warrants 0            
Period after business combination when warrants become exercisable 30 days            
Period after offering when warrants become exercisable 12 months            
Warrants exercisable expiration period after completion of business combination 5 years            
Net cash settlement value of warrants $ 0            
Redemption price per warrant $ 0.01            
Minimum period of prior written notice of redemption of warrants 30 days            
Minimum price per share required for redemption of warrants $ 18.00            
Warrants redemption covenant, threshold trading days 20 days            
Warrants redemption covenant, threshold consecutive trading days 30 days            
Warrants or rights outstanding 11,154,942 11,154,942          
Warrants | Minimum              
Class Of Stock [Line Items]              
Period allotted to complete the business combination 18 months            
Warrants | Maximum              
Class Of Stock [Line Items]              
Period allotted to complete the business combination 24 months