Consolidated Statements of Changes in Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock	Additional Capital	Retained Earnings	Accumulated Other Comprehensive Loss	Treasury Stock
Beginning Balance, Shares at Dec. 31, 2018		5,173,000
Beginning Balance, Value at Dec. 31, 2018	$ 285,092	$ 5,173	$ 31,971	$ 248,443	$ (127)	$ (368)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	17,865			17,865
Dividends paid	(23,028)			(23,028)
Change in fair value of interest rate cap	13				13
Ending Balance, Shares at Mar. 31, 2019		5,173,000
Ending Balance, Value at Mar. 31, 2019	$ 279,942	$ 5,173	31,971	243,280	(114)	(368)
Beginning Balance, Shares at Dec. 31, 2019	5,173,450	5,173,000
Beginning Balance, Value at Dec. 31, 2019	$ 253,515	$ 5,173	32,365	216,394	(49)	(368)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	4,572			4,572
Dividends paid	(23,034)			(23,034)
Change in fair value of interest rate cap	$ 25				25
Ending Balance, Shares at Mar. 31, 2020	5,173,450	5,173,000
Ending Balance, Value at Mar. 31, 2020	$ 235,078	$ 5,173	$ 32,365	$ 197,932	$ (24)	$ (368)