Consolidated Statements of Shareholders' Equity - USD ($) $ in Thousands	Common Stock	Preferred Stock 8% Preferred Stock	Preferred Stock 7% Preferred Stock	Preferred Stock 6% Preferred Stock	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Total
Balance at beginning of the period at Dec. 31, 2018	$ 135,057	$ 41,581			$ 244,909	$ (310)	$ 421,237
Balance at beginning of the period (in shares) at Dec. 31, 2018	28,694,036	41,625
Condensed Consolidated Statements of Shareholders’ Equity
Net income					10,570		10,570
Shares issued for stock compensation plans	$ 133						133
Shares issued for stock compensation plans (in shares)	10,127
Issuance of shares			$ 48,269				48,269
Issuance of shares (in shares)			2,000,000
Dividends on 8% preferred stock, annually					(833)		(833)
Dividends on common stock, annually					(2,009)		(2,009)
Other comprehensive income						464	464
Balance at end of the period at Mar. 31, 2019	$ 135,190	$ 41,581	$ 48,269		252,637	154	477,831
Balance at end of the period (in shares) at Mar. 31, 2019	28,704,163	41,625	2,000,000
Balance at beginning of the period at Dec. 31, 2019	$ 135,640	$ 41,581	$ 50,221	$ 120,844	304,984	458	653,728
Balance at beginning of the period (in shares) at Dec. 31, 2019	28,706,438	41,625	2,081,800	125,000
Condensed Consolidated Statements of Shareholders’ Equity
Net income					24,583		24,583
Shares issued for stock compensation plans	$ 106						106
Shares issued for stock compensation plans (in shares)	36,046
Dividends on 8% preferred stock, annually					(833)		(833)
Dividends on 7% preferred stock, annually					(910)		(910)
Dividends on 6% preferred stock, annually					(1,875)		(1,875)
Dividends on common stock, annually					(2,298)		(2,298)
Other comprehensive income						468	468
Balance at end of the period at Mar. 31, 2020	$ 135,746	$ 41,581	$ 50,221	$ 120,844	$ 323,651	$ 926	$ 672,969
Balance at end of the period (in shares) at Mar. 31, 2020	28,742,484	41,625	2,081,800	125,000