CONSOLIDATED STATEMENT OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Impact of adoption of CECL	Common Stock	Additional Paid-in Capital	Accumulated Earnings (Deficit)
Beginning Balance (in shares) at Dec. 31, 2018			28,755,665
Beginning Balance at Dec. 31, 2018	$ 425,587		$ 283	$ 421,739	$ 3,565
Increase (Decrease) in Stockholders' Equity
Stock-based compensation (in shares)			93,405
Stock-based compensation	492			492
Net income (loss)	8,543				8,543
Dividends declared	(9,520)				(9,520)
Ending Balance (in shares) at Mar. 31, 2019			28,849,070
Ending Balance at Mar. 31, 2019	425,102		$ 283	422,231	2,588
Beginning Balance (in shares) at Dec. 31, 2018			28,755,665
Beginning Balance at Dec. 31, 2018	425,587		$ 283	421,739	3,565
Increase (Decrease) in Stockholders' Equity
Net income (loss)	27,331
Ending Balance (in shares) at Sep. 30, 2019			28,865,610
Ending Balance at Sep. 30, 2019	$ 425,744		$ 283	423,137	2,324
Accounting Standards Update [Extensible List]	usgaap:AccountingStandardsUpdate201613Member
Beginning Balance (in shares) at Dec. 31, 2018			28,755,665
Beginning Balance at Dec. 31, 2018	$ 425,587		$ 283	421,739	3,565
Ending Balance (in shares) at Dec. 31, 2019	28,865,610		28,865,610
Ending Balance at Dec. 31, 2019	$ 426,339		$ 283	423,619	2,437
Beginning Balance (in shares) at Mar. 31, 2019			28,849,070
Beginning Balance at Mar. 31, 2019	425,102		$ 283	422,231	2,588
Increase (Decrease) in Stockholders' Equity
Stock-based compensation (in shares)			19,665
Stock-based compensation	427			427
Net income (loss)	9,755				9,755
Dividends declared	(9,527)				(9,527)
Ending Balance (in shares) at Jun. 30, 2019			28,868,735
Ending Balance at Jun. 30, 2019	425,757		$ 283	422,658	2,816
Increase (Decrease) in Stockholders' Equity
Stock-based compensation (in shares)			(3,125)
Stock-based compensation	479			479
Net income (loss)	9,034				9,034
Dividends declared	(9,526)				(9,526)
Ending Balance (in shares) at Sep. 30, 2019			28,865,610
Ending Balance at Sep. 30, 2019	425,744		$ 283	423,137	2,324
Increase (Decrease) in Stockholders' Equity
Stock-based compensation	482			482
Net income (loss)	9,660				9,660
Dividends declared	$ (9,547)				(9,547)
Ending Balance (in shares) at Dec. 31, 2019	28,865,610		28,865,610
Ending Balance at Dec. 31, 2019	$ 426,339		$ 283	423,619	2,437
Increase (Decrease) in Stockholders' Equity
Stock-based compensation (in shares)			(66,658)
Stock-based compensation	225			225
Net income (loss)	(17,263)				(17,263)
Offering costs	(341)			(341)
Dividends declared	(11,076)				(11,076)
Sale of common stock (in shares)			4,600,000
Sale of common stock	73,232		$ 46	73,186
Ending Balance (in shares) at Mar. 31, 2020			33,398,952
Ending Balance at Mar. 31, 2020	$ 466,065	$ (5,051)	$ 329	496,689	(30,953)
Accounting Standards Update [Extensible List]	usgaap:AccountingStandardsUpdate201613Member
Beginning Balance (in shares) at Dec. 31, 2019	28,865,610		28,865,610
Beginning Balance at Dec. 31, 2019	$ 426,339		$ 283	423,619	2,437
Increase (Decrease) in Stockholders' Equity
Net income (loss)	$ 7,433
Ending Balance (in shares) at Sep. 30, 2020	33,441,937		33,441,937
Ending Balance at Sep. 30, 2020	$ 469,349		$ 329	497,421	(28,401)
Beginning Balance (in shares) at Mar. 31, 2020			33,398,952
Beginning Balance at Mar. 31, 2020	466,065	$ (5,051)	$ 329	496,689	(30,953)
Increase (Decrease) in Stockholders' Equity
Stock-based compensation (in shares)			42,985
Stock-based compensation	365			365
Net income (loss)	9,768				9,768
Dividends declared	(11,072)				(11,072)
Ending Balance (in shares) at Jun. 30, 2020			33,441,937
Ending Balance at Jun. 30, 2020	465,126		$ 329	497,054	(32,257)
Increase (Decrease) in Stockholders' Equity
Stock-based compensation	367			367
Net income (loss)	14,928				14,928
Dividends declared	$ (11,072)				(11,072)
Ending Balance (in shares) at Sep. 30, 2020	33,441,937		33,441,937
Ending Balance at Sep. 30, 2020	$ 469,349		$ 329	$ 497,421	$ (28,401)