Non-Redeemable Preferred Stock - Additional Information (Detail) - $ / shares	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Preferred Stock [Line Items]
Number of shares of common stock for each share of converted preferred stock	anti-dilution terms of the Series B and Series D Preferred, the conversion ratio of the Series B Preferred increased to 43.3333 to 1 from 33.3333 to 1 and the Series D Preferred increased to 0.325 to 1 from 0.25 to 1
Series B Preferred Stock [Member]
Preferred Stock [Line Items]
Preferred stock, shares outstanding	20,000	20,000
Number of cumulative convertible preferred stock	20,000	20,000
Preferred stock cumulative dividend rate	12.00%	12.00%
Cash dividends paid on non-redeemable preferred stock per share	$ 12.00
Preferred stock, par value	$ 100	$ 100
Number of shares of common stock for each share of converted preferred stock	43.3333 shares of common stock for each share of preferred stock
Preferred stock converted into shares of common stock	866,666
Votes per share for preferred share holder	One vote per share
Series D Preferred Stock [Member]
Preferred Stock [Line Items]
Preferred stock, shares outstanding	1,000,000	1,000,000
Number of cumulative convertible preferred stock	1,000,000	1,000,000
Preferred stock cumulative dividend rate	6.00%	6.00%
Cash dividends paid on non-redeemable preferred stock per share	$ 0.06
Number of shares of common stock for each share of converted preferred stock	0.325 share of common stock for 1 share of preferred stock
Preferred stock converted into shares of common stock	325,000
Votes per share for preferred share holder	.875 votes per share
Preferred stock no par value
Liquidation preference of Series D preferred stock	$ 1.00