Consolidated Statements of Shareholders' Equity (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Dividends on preferred stock per share		$ 80.00	$ 80.00
Dividends on common stock per share	$ 0.28	$ 0.24	$ 0.20
8% Preferred Stock
Dividends on preferred stock per share	80.00
7% Preferred Stock
Dividends on preferred stock per share	$ 1.75
Offering expenses on issuance of stock	$ 1,824
6% Preferred Stock
Dividends on preferred stock per share	$ 60.00
Offering expenses on issuance of stock	$ 4,156