Condensed Consolidated Statement of Shareholders' Equity - USD ($) $ in Thousands	Common stock	Preferred stock 8% Preferred Stock	Preferred stock 7% Preferred Stock	Preferred stock 6% Series B Preferred Stock	Preferred stock 6% Series C Preferred Stock Common Stock Offering	Preferred stock 6% Series C Preferred Stock Private Placement	Preferred stock 6% Series C Preferred Stock	Retained Earnings Impact from adoption of ASU	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Total
Balance at beginning of the period at Dec. 31, 2020	$ 135,857	$ 41,581	$ 50,221						$ 461,744	$ 374
Balance at beginning of the period (in shares) at Dec. 31, 2020	43,120,625	41,625	2,081,800	125,000
Condensed Consolidated Statements of Shareholders' Equity
Net income									113,400		$ 113,400
Distribution to employee stock ownership plan	$ 537
Distribution to employee stock ownership plan (in shares)	29,149
Shares issued for stock compensation plans, net of taxes withheld to satisfy tax obligations	$ 442
Shares issued for stock compensation plans, net of taxes withheld to satisfy tax obligations (in shares)	25,625
Issuance of shares, net of offering expenses					$ 144,926	$ 46,158
Issuance of shares, net of offering expenses (in shares)					150,000	46,181
Dividends on 8% preferred stock, annually									(833)
Final dividend for redemption of 8% preferred stock									(139)
Dividends on 7% preferred stock, annually									(1,821)
Dividends on 6% Series B preferred stock, annually									(3,750)
Dividends on 6% Series C preferred stock, annually									(2,873)
Dividends on common stock, annually									(5,181)
Deconsolidation of entities									(419)
Redemption of 8% preferred stock		$ (41,581)							(45)
Redemption of 8% preferred stock (in shares)		(41,625)
Other comprehensive loss										(378)	(378)
Balance at end of the period at Jun. 30, 2021	$ 136,836		$ 50,221	$ 120,844			$ 191,084		560,083	(4)	$ 1,059,064
Balance at end of the period (in shares) at Jun. 30, 2021	43,175,399		2,081,800	125,000			196,181
Balance at beginning of the period at Mar. 31, 2021	$ 136,474	$ 41,581	$ 50,221	$ 120,844			$ 144,925		516,961	249
Balance at beginning of the period (in shares) at Mar. 31, 2021	43,173,209	41,625	2,081,800	125,000			150,000
Condensed Consolidated Statements of Shareholders' Equity
Repurchase of common Stock (in shares)											0
Net income									51,417		$ 51,417
Shares issued for stock compensation plans, net of taxes withheld to satisfy tax obligations	$ 362
Shares issued for stock compensation plans, net of taxes withheld to satisfy tax obligations (in shares)	2,190
Issuance of shares, net of offering expenses					$ 1	$ 46,158
Issuance of shares, net of offering expenses (in shares)						46,181
Dividends on 7% preferred stock, annually									(911)
Dividends on 6% Series B preferred stock, annually									(1,875)
Dividends on 6% Series C preferred stock, annually									(2,873)
Dividends on common stock, annually									(2,591)
Redemption of 8% preferred stock		$ (41,581)							(45)
Redemption of 8% preferred stock (in shares)		(41,625)
Other comprehensive loss										(253)	(253)
Balance at end of the period at Jun. 30, 2021	$ 136,836		$ 50,221	$ 120,844			$ 191,084		560,083	(4)	1,059,064
Balance at end of the period (in shares) at Jun. 30, 2021	43,175,399		2,081,800	125,000			196,181
Balance at beginning of the period at Dec. 31, 2021	$ 137,565		$ 50,221	$ 120,844			$ 191,084		657,149	(1,454)	1,155,409
Balance at beginning of the period (in shares) at Dec. 31, 2021	43,180,079		2,081,800	125,000			196,181
Condensed Consolidated Statements of Shareholders' Equity
Repurchase of common stock	$ (1,761)								(2,174)
Repurchase of common Stock (in shares)	(165,037)
Net income									104,077		104,077
Cash paid in lieu of fractional shares for stock split	$ (1)
Cash paid in lieu of fractional shares for stock split (in shares)	(29)
Distribution to employee stock ownership plan	$ 653
Distribution to employee stock ownership plan (in shares)	20,709
Shares issued for stock compensation plans, net of taxes withheld to satisfy tax obligations	$ 215
Shares issued for stock compensation plans, net of taxes withheld to satisfy tax obligations (in shares)	70,783
Dividends on 7% preferred stock, annually									(1,821)
Dividends on 6% Series B preferred stock, annually									(3,750)
Dividends on 6% Series C preferred stock, annually									(5,886)
Dividends on common stock, annually									(6,048)
Other comprehensive loss										(6,616)	(6,616)
Balance at end of the period (ASU 2016-13) at Jun. 30, 2022								$ (3,648)
Balance at end of the period (ASU 2016-02) at Jun. 30, 2022								(110)
Balance at end of the period at Jun. 30, 2022	$ 136,671		$ 50,221	$ 120,844			$ 191,084		737,789	(8,070)	1,228,539
Balance at end of the period (in shares) at Jun. 30, 2022	43,106,505		2,081,800	125,000			196,181
Balance at beginning of the period at Mar. 31, 2022	$ 137,882		$ 50,221	$ 120,844			$ 191,084		694,776	(6,304)
Balance at beginning of the period (in shares) at Mar. 31, 2022	43,267,776		2,081,800	125,000			196,181
Condensed Consolidated Statements of Shareholders' Equity
Repurchase of common stock	$ (1,761)								(2,174)
Repurchase of common Stock (in shares)	(165,037)
Net income									53,935		53,935
Shares issued for stock compensation plans, net of taxes withheld to satisfy tax obligations	$ 550
Shares issued for stock compensation plans, net of taxes withheld to satisfy tax obligations (in shares)	3,766
Dividends on 7% preferred stock, annually									(911)
Dividends on 6% Series B preferred stock, annually									(1,875)
Dividends on 6% Series C preferred stock, annually									(2,943)
Dividends on common stock, annually									(3,019)
Other comprehensive loss										(1,766)	(1,766)
Balance at end of the period (ASU 2016-13) at Jun. 30, 2022								(3,648)
Balance at end of the period (ASU 2016-02) at Jun. 30, 2022								$ (110)
Balance at end of the period at Jun. 30, 2022	$ 136,671		$ 50,221	$ 120,844			$ 191,084		$ 737,789	$ (8,070)	$ 1,228,539
Balance at end of the period (in shares) at Jun. 30, 2022	43,106,505		2,081,800	125,000			196,181