CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY - USD ($) $ in Thousands	Total	Common Stock	Additional Capital	Retained Earnings	Accumulated  Other Comprehensive Income	Treasury Stock
Beginning balance, (in shares) at Dec. 31, 2022		5,173,000
Beginning balance, value at Dec. 31, 2022	$ 236,499	$ 5,173	$ 33,865	$ 172,243	$ 25,586	$ (368)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	86,127			86,127
Dividends paid	(69,232)			(69,232)
Change in fair value of interest rate derivatives and other	(2,020)				(2,020)
Deferred stock unit grants	450		450
Ending balance, (in shares) at Sep. 30, 2023		5,173,000
Ending balance, value at Sep. 30, 2023	251,824	$ 5,173	34,315	189,138	23,566	(368)
Beginning balance, (in shares) at Jun. 30, 2023		5,173,000
Beginning balance, value at Jun. 30, 2023	265,644	$ 5,173	34,315	201,472	25,052	(368)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	10,754			10,754
Dividends paid	(23,088)			(23,088)
Change in fair value of interest rate derivatives and other	(1,486)				(1,486)
Ending balance, (in shares) at Sep. 30, 2023		5,173,000
Ending balance, value at Sep. 30, 2023	$ 251,824	$ 5,173	34,315	189,138	23,566	(368)
Beginning balance, (in shares) at Dec. 31, 2023	5,173,450	5,173,000
Beginning balance, value at Dec. 31, 2023	$ 237,657	$ 5,173	34,315	182,336	16,201	(368)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	31,167			31,167
Dividends paid	(69,277)			(69,277)
Change in fair value of interest rate derivatives and other	(9,308)				(9,308)
Deferred stock unit grants	$ 450		450
Ending balance, (in shares) at Sep. 30, 2024	5,173,450	5,173,000
Ending balance, value at Sep. 30, 2024	$ 190,689	$ 5,173	34,765	144,226	6,893	(368)
Beginning balance, (in shares) at Jun. 30, 2024		5,173,000
Beginning balance, value at Jun. 30, 2024	212,520	$ 5,173	34,765	160,649	12,301	(368)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	6,678			6,678
Dividends paid	(23,101)			(23,101)
Change in fair value of interest rate derivatives and other	$ (5,408)				(5,408)
Ending balance, (in shares) at Sep. 30, 2024	5,173,450	5,173,000
Ending balance, value at Sep. 30, 2024	$ 190,689	$ 5,173	$ 34,765	$ 144,226	$ 6,893	$ (368)