CONSOLIDATED BALANCE SHEETS (UNAUDITED) (Parenthetical) - $ / shares	6 Months Ended	12 Months Ended
	Apr. 30, 2017	Oct. 31, 2016
Stockholders' Equity:
Excess stock, par value (in dollars per share)	$ 0.01	$ 0.01
Excess stock, shares authorized (in shares)	20,000,000	20,000,000
Excess stock, shares issued (in shares)	0	0
Excess stock, shares outstanding (in shares)	0	0
7.125% Series F Cumulative Preferred Stock [Member]
Stockholders' Equity:
Preferred stock, dividend rate	7.125%	7.125%
Preferred stock, liquidation preference (in dollars per share)	$ 25	$ 25
Preferred stock, shares issued (in shares)	5,175,000	5,175,000
Preferred Stock, shares outstanding (in shares)	5,175,000	5,175,000
Series G Cumulative Preferred Stock [Member]
Stockholders' Equity:
Preferred stock, dividend rate	6.75%	6.75%
Preferred stock, liquidation preference (in dollars per share)	$ 25	$ 25
Preferred stock, shares issued (in shares)	3,000,000	3,000,000
Preferred Stock, shares outstanding (in shares)	3,000,000	3,000,000
Common Stock [Member]
Stockholders' Equity:
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	30,000,000	30,000,000
Common stock, shares issued (in shares)	9,662,496	9,507,973
Common stock, shares outstanding (in shares)	9,662,496	9,507,973
Class A Common Stock [Member]
Stockholders' Equity:
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	100,000,000	100,000,000
Common stock, shares issued (in shares)	29,730,172	29,633,520
Common stock, shares outstanding (in shares)	29,730,172	29,633,520