Unaudited Consolidated Statements of Changes in Shareholders' Equity Statement - USD ($) $ in Thousands	Total	Common shares	Additional paid-in capital	Accumulated other comprehensive income (loss)	Unrealized holding gains (losses) of available for sale investments	Currency translation adjustment	Common shares held in treasury, at cost	Retained earnings (deficit)
Cumulative effect of adoption of updated accounting guidance for credit losses at January 1, 2020								$ 0
Balance, beginning of period at Dec. 31, 2018		$ 227	$ 895,386	$ (4,730)	$ (4,158)	$ (572)	$ 0	(1,275)
Common shares issued		0	250
Share compensation expense			2,080
Unrealized holding gains (losses) of available for sale investments, net of reclassification adjustments	$ 7,854				7,854
Currency translation adjustment	47					47
Shares repurchased for treasury							0
Net income (loss) before preference dividends	71,272							71,272
Preferred share dividends paid and accrued	(9,815)							(9,815)
Balance, end of period at Jun. 30, 2019	961,296	227	897,716	3,171	3,696	(525)	0	60,182
Cumulative effect of adoption of updated accounting guidance for credit losses at January 1, 2020								0
Balance, beginning of period at Mar. 31, 2019		227	895,386	(79)	658	(737)	0	46,357
Common shares issued		0	250
Share compensation expense			2,080
Unrealized holding gains (losses) of available for sale investments, net of reclassification adjustments	3,038				3,038
Currency translation adjustment	212					212
Shares repurchased for treasury							0
Net income (loss) before preference dividends	18,733							18,733
Preferred share dividends paid and accrued	(4,908)							(4,908)
Balance, end of period at Jun. 30, 2019	961,296	227	897,716	3,171	3,696	(525)	0	60,182
Cumulative effect of adoption of updated accounting guidance for credit losses at January 1, 2020								(428)
Balance, beginning of period at Dec. 31, 2019	872,353	227	898,083	5,629	6,252	(623)	(75,056)	43,470
Common shares issued		0	491
Share compensation expense			361
Unrealized holding gains (losses) of available for sale investments, net of reclassification adjustments	(14,996)				(14,996)
Currency translation adjustment	188					188
Shares repurchased for treasury	(77,900)						(2,867)
Net income (loss) before preference dividends	(76,671)							(76,671)
Preferred share dividends paid and accrued	(2,280)							(2,280)
Balance, end of period at Jun. 30, 2020	776,151	227	898,935	(9,179)	(8,744)	(435)	(77,923)	(35,909)
Cumulative effect of adoption of updated accounting guidance for credit losses at January 1, 2020								0
Balance, beginning of period at Mar. 31, 2020		227	898,693	(32,206)	(31,720)	(486)	(77,923)	(224,737)
Common shares issued		0	241
Share compensation expense			1
Unrealized holding gains (losses) of available for sale investments, net of reclassification adjustments	22,976				22,976
Currency translation adjustment	51					51
Shares repurchased for treasury							0
Net income (loss) before preference dividends	189,937							189,937
Preferred share dividends paid and accrued	(1,109)							(1,109)
Balance, end of period at Jun. 30, 2020	$ 776,151	$ 227	$ 898,935	$ (9,179)	$ (8,744)	$ (435)	$ (77,923)	$ (35,909)