Quarterly Financial Information (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2023	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Quarterly Financial Information
Revenues	$ 50,195	$ 49,303	$ 48,246	$ 49,500	$ 47,839	$ 43,503	$ 43,024	$ 40,787	$ 197,244	$ 175,153	$ 155,322
Net income available to common stockholders	$ 28,057	$ 22,050	$ 6,028	$ 32,929	$ 17,809	$ 13,159	$ 54,065	$ 14,275
Net income per common share available to common stockholders:
Basic (in dollars per share)	$ 0.67	$ 0.54	$ 0.15	$ 0.80	$ 0.44	$ 0.33	$ 1.37	$ 0.36	$ 2.16	$ 2.49	$ 1.41
Diluted (in dollars per share)	0.67	0.54	0.15	0.80	0.44	0.32	1.36	0.36	2.16	2.48	1.41
Dividends per share declared (in dollars per share)	0.57	0.57	0.57	0.57	0.57	0.57	0.57	0.57
Dividends declared and paid per common share (in dollars per share)	$ 0.57	$ 0.57	$ 0.57	$ 0.57	$ 0.57	$ 0.57	$ 0.57	$ 0.57	$ 2.280	$ 2.280	$ 2.280