CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY - USD ($)	Total	Total Stockholders' Equity	Common stock	Treasury stock	Additional Paid-in Capital	Retained Earnings	Accumulated other comprehensive income/(loss)	Non-controlling Interest	Preferred stock - Series A shares	Preferred stock - Series B shares
Preferred Stock - beginning balance (in shares) at Dec. 31, 2019									0	0
Preferred stock - beginning balance at Dec. 31, 2019									$ 0	$ 0
Beginning balance (in shares) at Dec. 31, 2019			22,142,143
Beginning balance at Dec. 31, 2019	$ 384,084,000	$ 359,882,000	$ 222,000	$ (458,000)	$ 309,395,000	$ 49,446,000	$ 1,277,000	$ 24,202,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Consolidated net income attributable to Company		400,000				400,000
Net income	1,496,000							1,096,000
Issuance of shares of subsidiary	145,000	145,000			145,000
Stock-based compensation expense (in shares)			2,600
Stock-based compensation expense	214,000	214,000			214,000
Dividends declared and distributions (in shares)			781,222
Dividends declared and distributions	(84,000)		$ 8,000		7,089,000	(7,097,000)		(84,000)
Convertible senior notes repurchase	(81,000)	(81,000)			(81,000)
Other comprehensive income/(loss)	(28,444,000)	(28,444,000)					(28,444,000)
Treasury stock (in shares)			(4,030)
Treasury stock	(56,000)	(56,000)		(56,000)
Preferred Stock - ending balance (in shares) at Mar. 31, 2020									0	0
Preferred stock - ending balance at Mar. 31, 2020									$ 0	$ 0
Ending balance (in shares) at Mar. 31, 2020			22,921,935
Ending balance at Mar. 31, 2020	357,274,000	332,060,000	$ 230,000	(514,000)	316,762,000	42,749,000	(27,167,000)	25,214,000
Preferred Stock - beginning balance (in shares) at Dec. 31, 2019									0	0
Preferred stock - beginning balance at Dec. 31, 2019									$ 0	$ 0
Beginning balance (in shares) at Dec. 31, 2019			22,142,143
Beginning balance at Dec. 31, 2019	384,084,000	359,882,000	$ 222,000	(458,000)	309,395,000	49,446,000	1,277,000	24,202,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Consolidated net income attributable to Company	15,713,000
Net income	19,206,000
Issuance of shares under dividend reinvestment plan (in shares)			9,985
Treasury stock	(164,000)
Preferred Stock - ending balance (in shares) at Sep. 30, 2020									2,307,400	2,892,600
Preferred stock - ending balance at Sep. 30, 2020									$ 51,100,000	$ 64,044,000
Ending balance (in shares) at Sep. 30, 2020			23,034,443
Ending balance at Sep. 30, 2020	506,346,000	478,878,000	$ 231,000	(634,000)	317,295,000	46,441,000	401,000	27,468,000
Preferred Stock - beginning balance (in shares) at Mar. 31, 2020									0	0
Preferred stock - beginning balance at Mar. 31, 2020									$ 0	$ 0
Beginning balance (in shares) at Mar. 31, 2020			22,921,935
Beginning balance at Mar. 31, 2020	357,274,000	332,060,000	$ 230,000	(514,000)	316,762,000	42,749,000	(27,167,000)	25,214,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Consolidated net income attributable to Company		8,083,000				8,083,000
Net income	8,818,000							735,000
Preferred stock (in shares)									2,307,400	2,892,600
Preferred Stock	115,144,000	115,144,000							$ 51,100,000	$ 64,044,000
Issuance of shares under dividend reinvestment plan (in shares)			5,057
Issuance of shares under dividend reinvestment plan	41,000	41,000			41,000
Stock-based compensation expense (in shares)			3,468
Stock-based compensation expense	214,000	214,000			214,000
Dividends declared and distributions	(5,814,000)	(5,748,000)				(5,748,000)		(66,000)
Other comprehensive income/(loss)	23,231,000	23,231,000					23,231,000
Treasury stock (in shares)			(5,478)
Treasury stock	(38,000)	(38,000)		(50,000)	12,000
Preferred Stock - ending balance (in shares) at Jun. 30, 2020									2,307,400	2,892,600
Preferred stock - ending balance at Jun. 30, 2020									$ 51,100,000	$ 64,044,000
Ending balance (in shares) at Jun. 30, 2020			22,924,982
Ending balance at Jun. 30, 2020	498,870,000	472,987,000	$ 230,000	(564,000)	317,029,000	45,084,000	(3,936,000)	25,883,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Consolidated net income attributable to Company	7,230,000	7,230,000				7,230,000
Net income	8,892,000							1,662,000
Issuance of shares under dividend reinvestment plan (in shares)			4,928
Issuance of shares under dividend reinvestment plan	45,000	45,000			45,000
Stock-based compensation expense (in shares)			111,950
Stock-based compensation expense	222,000	222,000	$ 1,000		221,000
Dividends declared and distributions	(5,950,000)	(5,873,000)				(5,873,000)		(77,000)
Convertible senior notes repurchase	0
Other comprehensive income/(loss)	4,337,000	4,337,000					4,337,000
Treasury stock (in shares)			(7,417)
Treasury stock	(70,000)	(70,000)		(70,000)
Preferred Stock - ending balance (in shares) at Sep. 30, 2020									2,307,400	2,892,600
Preferred stock - ending balance at Sep. 30, 2020									$ 51,100,000	$ 64,044,000
Ending balance (in shares) at Sep. 30, 2020			23,034,443
Ending balance at Sep. 30, 2020	$ 506,346,000	478,878,000	$ 231,000	(634,000)	317,295,000	46,441,000	401,000	27,468,000
Preferred Stock - beginning balance (in shares) at Dec. 31, 2020									2,307,400	2,892,600
Preferred stock - beginning balance at Dec. 31, 2020									$ 51,100,000	$ 64,044,000
Beginning balance (in shares) at Dec. 31, 2020	22,978,339		22,978,339
Beginning balance at Dec. 31, 2020	$ 514,491,000	485,361,000	$ 231,000	(1,159,000)	317,424,000	53,346,000	375,000	29,130,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Consolidated net income attributable to Company		8,953,000				8,953,000
Net income	10,642,000							1,689,000
Issuance of shares under dividend reinvestment plan (in shares)			4,228
Issuance of shares under dividend reinvestment plan	47,000	47,000			47,000
Stock-based compensation expense (in shares)			6,280
Stock-based compensation expense	294,000	294,000			294,000
Dividends declared and distributions	(5,883,000)	(5,799,000)				(5,799,000)		(84,000)
Acquisition of non-controlling interest in subsidiary and distribution to non-controlling interest	11,362,000	3,056,000			3,056,000			8,306,000
Convertible senior notes repurchase	0
Other comprehensive income/(loss)	1,306,000	1,306,000					1,306,000
Preferred Stock - ending balance (in shares) at Mar. 31, 2021									2,307,400	2,892,600
Preferred stock - ending balance at Mar. 31, 2021									$ 51,100,000	$ 64,044,000
Ending balance (in shares) at Mar. 31, 2021			22,988,847
Ending balance at Mar. 31, 2021	$ 509,535,000	487,106,000	$ 231,000	(1,159,000)	314,709,000	56,500,000	1,681,000	22,429,000
Preferred Stock - beginning balance (in shares) at Dec. 31, 2020									2,307,400	2,892,600
Preferred stock - beginning balance at Dec. 31, 2020									$ 51,100,000	$ 64,044,000
Beginning balance (in shares) at Dec. 31, 2020	22,978,339		22,978,339
Beginning balance at Dec. 31, 2020	$ 514,491,000	485,361,000	$ 231,000	(1,159,000)	317,424,000	53,346,000	375,000	29,130,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Consolidated net income attributable to Company	32,543,000
Net income	32,496,000
Issuance of shares under dividend reinvestment plan (in shares)			13,097
Treasury stock	$ (380,000)
Preferred Stock - ending balance (in shares) at Sep. 30, 2021									2,307,400	2,892,600
Preferred stock - ending balance at Sep. 30, 2021									$ 51,100,000	$ 64,044,000
Ending balance (in shares) at Sep. 30, 2021	23,140,131		23,140,131
Ending balance at Sep. 30, 2021	$ 503,105,000	499,824,000	$ 232,000	(1,539,000)	315,611,000	66,958,000	3,418,000	3,281,000
Preferred Stock - beginning balance (in shares) at Mar. 31, 2021									2,307,400	2,892,600
Preferred stock - beginning balance at Mar. 31, 2021									$ 51,100,000	$ 64,044,000
Beginning balance (in shares) at Mar. 31, 2021			22,988,847
Beginning balance at Mar. 31, 2021	509,535,000	487,106,000	$ 231,000	(1,159,000)	314,709,000	56,500,000	1,681,000	22,429,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Consolidated net income attributable to Company		12,328,000				12,328,000
Net income	11,170,000							(1,158,000)
Issuance of shares under dividend reinvestment plan (in shares)			3,820
Issuance of shares under dividend reinvestment plan	48,000	48,000			48,000
Stock-based compensation expense (in shares)			19,945
Stock-based compensation expense	374,000	374,000			374,000
Dividends declared and distributions	(6,495,000)	(6,326,000)				(6,326,000)		(169,000)
Acquisition of non-controlling interest in subsidiary and distribution to non-controlling interest	(16,864,000)							(16,864,000)
Convertible senior notes repurchase	0
Other comprehensive income/(loss)	(30,000)	(30,000)					(30,000)
Treasury stock (in shares)			(19,366)
Treasury stock	(246,000)	(246,000)		(246,000)
Preferred Stock - ending balance (in shares) at Jun. 30, 2021									2,307,400	2,892,600
Preferred stock - ending balance at Jun. 30, 2021									$ 51,100,000	$ 64,044,000
Ending balance (in shares) at Jun. 30, 2021			22,993,246
Ending balance at Jun. 30, 2021	497,492,000	493,254,000	$ 231,000	(1,405,000)	315,131,000	62,502,000	1,651,000	4,238,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Consolidated net income attributable to Company	11,262,000	11,262,000				11,262,000
Net income	10,684,000							(578,000)
Sale of shares (in shares)			9,073
Sale of shares	99,000	99,000			99,000
Issuance of shares under dividend reinvestment plan (in shares)			5,049
Issuance of shares under dividend reinvestment plan	71,000	71,000			71,000
Stock-based compensation expense (in shares)			142,557
Stock-based compensation expense	311,000	311,000	$ 1,000		310,000
Dividends declared and distributions	(6,878,000)	(6,806,000)				(6,806,000)		(72,000)
Acquisition of non-controlling interest in subsidiary and distribution to non-controlling interest	(307,000)							(307,000)
Other comprehensive income/(loss)	1,767,000	1,767,000					1,767,000
Treasury stock (in shares)			(9,794)
Treasury stock	$ (134,000)	(134,000)		(134,000)
Preferred Stock - ending balance (in shares) at Sep. 30, 2021									2,307,400	2,892,600
Preferred stock - ending balance at Sep. 30, 2021									$ 51,100,000	$ 64,044,000
Ending balance (in shares) at Sep. 30, 2021	23,140,131		23,140,131
Ending balance at Sep. 30, 2021	$ 503,105,000	$ 499,824,000	$ 232,000	$ (1,539,000)	$ 315,611,000	$ 66,958,000	$ 3,418,000	$ 3,281,000