CONDENSED CONSOLIDATED STATEMENT OF STOCKHOLDERS' EQUITY, (Unaudited) - USD ($)	Total	Common Stock [Member]	Additional Paid In Capital [Member]	Retained Earnings [Member]
Balances at Dec. 31, 2017	$ 462,211,000	$ 531,000	$ 461,680,000	$ 0
Increase (Decrease) in Stockholders' Equity
Net income		0	0	(16,377,000)
Cash dividend declared	(16,463,000)	0	(16,463,000)	0
Issuance of common shares pursuant to stock based compensation plan	35,000	0	35,000	0
Amortization of stock based compensation	45,000	0	45,000	0
Balances at Mar. 31, 2018	429,451,000	531,000	445,297,000	(16,377,000)
Balances at Dec. 31, 2017	462,211,000	531,000	461,680,000	0
Increase (Decrease) in Stockholders' Equity
Net income	(15,030,000)
Balances at Jun. 30, 2018	429,451,000	531,000	445,297,000	(16,377,000)
Balances at Mar. 31, 2018	429,451,000	531,000	445,297,000	(16,377,000)
Increase (Decrease) in Stockholders' Equity
Net income	1,347,000	0	0	1,347,000
Cash dividend declared	(14,161,000)	0	(14,161,000)	0
Issuance of common shares pursuant to stock based compensation plan	184,000	0	184,000	0
Amortization of stock based compensation	59,000	0	59,000	0
Stock Repurchased and Retired During Period, Value	(7,681,000)	(11,000)	(7,670,000)	0
Balances at Jun. 30, 2018	429,451,000	531,000	445,297,000	(16,377,000)
Balances at Dec. 31, 2018	336,079,000	491,000	379,975,000	(44,387,000)
Increase (Decrease) in Stockholders' Equity
Net income	10,597,000	0	0	10,597,000
Cash dividend declared	(11,824,000)	0	(11,824,000)	0
Issuance of common stock pursuant to public offerings, net	8,503,000	13,000	8,490,000	0
Issuance of common shares pursuant to stock based compensation plan	41,000	0	41,000	0
Amortization of stock based compensation	42,000	0	42,000	0
Stock Repurchased and Retired During Period, Value	(3,024,000)	(5,000)	(3,019,000)	0
Balances at Mar. 31, 2019	340,414,000	499,000	373,705,000	(33,790,000)
Balances at Dec. 31, 2018	336,079,000	491,000	379,975,000	(44,387,000)
Increase (Decrease) in Stockholders' Equity
Net income	14,130,000
Balances at Jun. 30, 2019	359,658,000	543,000	389,372,000	(30,257,000)
Balances at Mar. 31, 2019	340,414,000	499,000	373,705,000	(33,790,000)
Increase (Decrease) in Stockholders' Equity
Net income	3,533,000	0	0	3,533,000
Cash dividend declared	12,859,000	0	12,859,000	0
Issuance of common stock pursuant to public offerings, net	28,495,000	44,000	28,451,000	0
Issuance of common shares pursuant to stock based compensation plan	43,000	0	43,000	0
Amortization of stock based compensation	32,000	0	32,000	0
Balances at Jun. 30, 2019	$ 359,658,000	$ 543,000	$ 389,372,000	$ (30,257,000)