Note 15 - Stockholders' Equity (Tables)

3 Months Ended

Mar. 31, 2019

Notes Tables

Schedule of Stockholders Equity [Table Text Block]

As of March 31, 2019 and December 31, 2018
Class of Preferred Stock	Shares Authorized		Shares Issued and Outstanding		Liquidation Preference (in thousands)		Dividend Rate			Annual Dividend per Depositary Share		Par Value		Optional Redemption Date
Class I		18,400		7,000	$	175,000		6.000	%	$	1.50000	$	1.00	3/20/2017
Class J		9,000		9,000		225,000		5.500	%	$	1.37500	$	1.00	7/25/2017
Class K		8,050		7,000		175,000		5.625	%	$	1.40625	$	1.00	12/7/2017
Class L		10,350		9,000		225,000		5.125	%	$	1.28125	$	1.00	8/16/2022
Class M		10,580		10,580		264,500		5.250	%	$	1.31250	$	1.00	12/20/2022
				42,580	$	1,064,500

Dividends Declared [Table Text Block]

	Three Months Ended March 31,
	2019		2018
Common Shares	$	0.2800	$	0.2800
Class I Depositary Shares	$	0.3750	$	0.3750
Class J Depositary Shares	$	0.3438	$	0.3438
Class K Depositary Shares	$	0.3516	$	0.3516
Class L Depositary Shares	$	0.3203	$	0.3203
Class M Depositary Shares	$	0.3281	$	0.3281