Related Party Transaction - Additional Information (Detail) - USD ($)	1 Months Ended	3 Months Ended		12 Months Ended
	Jan. 31, 2020	Apr. 30, 2021	Apr. 30, 2020	Jan. 31, 2020	Jan. 31, 2021	Sep. 30, 2020	Aug. 03, 2020	Aug. 02, 2020	Dec. 18, 2019
Related Party Transaction [Line Items]
Maximum number of preferred stock to be issued (in shares)		2,000,000			2,000,000		2,000,000	1,000,000
Preferred stock, par value (in usd per share)		$ 1.00			$ 1.00
Maximum number of common stock to be issued (in shares)		40,000,000			40,000,000		40,000,000	20,000,000
Common stock, par value (in usd per share)		$ 0.01			$ 0.01
Net proceeds from common stock offering		$ 42,000	$ 0
Ladenburg Thalmann & Co. Inc.
Related Party Transaction [Line Items]
Maximum number of common stock to be issued (in shares)						5,000,000
Common stock, par value (in usd per share)						$ 0.01
Series A Preferred Stock | Non-Executive Chairman
Related Party Transaction [Line Items]
Equity distribution compensation expenses		$ 0
Series A Preferred Stock | Ladenburg Thalmann & Co. Inc.
Related Party Transaction [Line Items]
Maximum number of preferred stock to be issued (in shares)						500,000			500,000
Preferred stock dividend rate	9.00%
Preferred stock, par value (in usd per share)									$ 1.00
Percentage of compensation fees to be paid	2.00%
Stock issued during period (in shares)	994,046	20,960
Preferred stock issued from at the market sale of stock program (as a percent)				100.00%
Net proceeds from preferred stock		$ 503,000
Equity distribution compensation expenses		10,000
Common Stock | Non-Executive Chairman
Related Party Transaction [Line Items]
Equity distribution compensation expenses		$ 0
Common Stock | Ladenburg Thalmann & Co. Inc.
Related Party Transaction [Line Items]
Stock issued during period (in shares)		18,053
Equity distribution compensation expenses		$ 1,000
Net proceeds from common stock offering		$ 42,000