CONSOLIDATED BALANCE SHEETS (Unaudited) (Parenthetical) - USD ($)	Sep. 30, 2023	Dec. 31, 2022
Intangible assets, accumulated amortization	$ 23,851,000	$ 23,029,000
Common stock, par value (in dollars per share)	$ 1	$ 1
Common stock, shares authorized (in shares)	13,333,000	13,333,000
Common stock, shares issued (in shares)	5,341,000	5,356,000
Common stock, shares outstanding (in shares)	5,341,000	5,356,000
Series B Preferred Stock
Preferred shares, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares issued (in shares)	3,450,000	3,450,000
Preferred shares, outstanding (in shares)	3,450,000	3,450,000
Liquidation preference	$ 106,921,000	$ 102,151,000
Series C Preferred Stock
Preferred shares, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares issued (in shares)	6,900,000	6,900,000
Preferred shares, outstanding (in shares)	6,900,000	6,900,000
Liquidation preference	$ 212,865,000	$ 203,550,000
Series D Preferred Stock
Preferred shares, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares issued (in shares)	5,000,000	5,000,000
Preferred shares, outstanding (in shares)	5,000,000	5,000,000
Liquidation preference	$ 152,931,000	$ 146,485,000