Quarterly report pursuant to Section 13 or 15(d)

Income Taxes - Additional Information (Detail)

v3.19.1
Income Taxes - Additional Information (Detail) - USD ($)
$ in Thousands
1 Months Ended 3 Months Ended 11 Months Ended
Mar. 04, 2019
Jan. 31, 2018
Apr. 30, 2019
Apr. 30, 2018
Dec. 31, 2017
Income Tax Disclosure [Abstract]          
Income tax expense (benefit)     $ 402 $ (494)  
Corporate federal income tax rate   21.00%     35.00%
Preferred shares purchase rights, declared date as dividend Mar. 04, 2019        
Preferred shares purchase rights for each common stock 1        
Preferred shares purchase rights, record date as dividend Mar. 15, 2019