CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income (Loss)	Cumulative Earnings	Cumulative Distributions to Stockholders
Beginning balance (in shares) at Dec. 31, 2018		84,884,344
Balance at beginning of period at Dec. 31, 2018	$ 1,348,794	$ 849	$ 1,811,422	$ 61,297	$ 1,409,941	$ (1,934,715)
Increase (Decrease) in Stockholders' Equity
Net (Loss) Income	54,464				54,464
Other comprehensive loss	(8,613)			(8,613)
Issuance of common stock (in shares)		11,500,000
Issuance of common stock	177,597	$ 115	177,482
Direct stock purchase and dividend reinvestment plan (in shares)		399,838
Direct stock purchase and dividend reinvestment plan	6,307	$ 4	6,303
Employee stock purchase and incentive plans (in shares)		82,282
Employee stock purchase and incentive plans	(1,938)	$ 1	(1,939)
Non-cash equity award compensation	3,090		3,090
Common dividends declared	(29,774)					(29,774)
Ending balance (in shares) at Mar. 31, 2019		96,866,464
Balance at End of Period at Mar. 31, 2019	1,549,927	$ 969	1,996,358	52,684	1,464,405	(1,964,489)
Beginning balance (in shares) at Dec. 31, 2019		114,353,036
Balance at beginning of period at Dec. 31, 2019	1,827,231	$ 1,144	2,269,617	41,513	1,579,124	(2,064,167)
Increase (Decrease) in Stockholders' Equity
Net (Loss) Income	(943,398)				(943,398)
Other comprehensive loss	(127,044)			(127,044)
Issuance of common stock (in shares)		350,088
Issuance of common stock	5,547	$ 3	5,544
Direct stock purchase and dividend reinvestment plan (in shares)		0
Employee stock purchase and incentive plans (in shares)		134,409
Employee stock purchase and incentive plans	(2,540)	$ 1	(2,541)
Non-cash equity award compensation	3,188		3,188
Common dividends declared	(37,782)					(37,782)
Ending balance (in shares) at Mar. 31, 2020		114,837,533
Balance at End of Period at Mar. 31, 2020	$ 725,202	$ 1,148	$ 2,275,808	$ (85,531)	$ 635,726	$ (2,101,949)