Note 15 - Stockholders' Equity (Details Textual) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2023	Dec. 31, 2022
Preferred Stock, Par or Stated Value Per Share (in dollars per share)	$ 1.00	$ 1.00
Common Stock, Par or Stated Value Per Share (in dollars per share)	$ 0.01	$ 0.01
Class L Cumulative Redeemable Preferred Stock Depositary Shares[Member]
Stock Repurchased During Period, Shares (in shares)	5,540
Class M Cumulative Redeemable Preferred Stock Depositary Shares [Member]
Stock Repurchased During Period, Shares (in shares)	7,741
Share Repurchase Program [Member]
Preferred Stock, Par or Stated Value Per Share (in dollars per share)	$ 1.00
Common Stock, Par or Stated Value Per Share (in dollars per share)	$ 0.01
Stock Repurchase Program, Authorized Amount	$ 300.0
Stock Repurchased During Period, Shares (in shares)	0
Stock Repurchase Program, Remaining Authorized Repurchase Amount	$ 224.9
Share Repurchase Program [Member] | Maximum [Member]
Stock Repurchase Program, Number of Shares Authorized to be Repurchased (in shares)	1,942
Share Repurchase Program [Member] | Class L Cumulative Redeemable Preferred Stock Depositary Shares[Member] | Maximum [Member]
Stock Repurchase Program, Number of Shares Authorized to be Repurchased (in shares)	894,000
Share Repurchase Program [Member] | Class M Cumulative Redeemable Preferred Stock Depositary Shares [Member] | Maximum [Member]
Stock Repurchase Program, Number of Shares Authorized to be Repurchased (in shares)	1,048,000