Consolidated Statements of Stockholders' Equity - USD ($)	Total	Common Stock [Member]	8.25% Series A Cumulative Redeemable Preferred Stock [Member]	8.00% Series B Cumulative Redeemable Preferred Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings (Deficit) [Member]
Balance at Dec. 31, 2012	$ 794,621,781	$ 269,620	$ 49,920,772	$ 111,293,233	$ 552,067,681	$ 81,070,475
Balance (in shares) at Dec. 31, 2012		26,961,936
Net proceeds from issuance of common stock	33,176,288	$ 13,817	0	0	33,162,471	0
Net proceeds from issuance of common stock (in shares)		1,381,739
Grant of restricted stock and amortization of equity based compensation	389,556	$ 220	0	0	389,336	0
Grant of restricted stock and amortization of equity based compensation (in shares)		21,980
Common dividends declared	(78,708,839)	$ 0	0	0	0	(78,708,839)
Preferred Series A dividends declared	(4,269,416)	0	0	0	0	(4,269,416)
Preferred Series B dividends declared	(9,200,000)	0	0	0	0	(9,200,000)
Net Income/(Loss)	(31,578,636)	0	0	0	0	(31,578,636)
Balance at Dec. 31, 2013	704,430,734	$ 283,657	49,920,772	111,293,233	585,619,488	(42,686,416)
Balance (in shares) at Dec. 31, 2013		28,365,655
Grant of restricted stock and amortization of equity based compensation	432,467	$ 204	0	0	432,263	0
Grant of restricted stock and amortization of equity based compensation (in shares)		20,360
Common dividends declared	(68,114,210)	$ 0	0	0	0	(68,114,210)
Preferred Series A dividends declared	(4,269,416)	0	0	0	0	(4,269,416)
Preferred Series B dividends declared	(9,200,000)	0	0	0	0	(9,200,000)
Net Income/(Loss)	109,395,568	0	0	0	0	109,395,568
Balance at Dec. 31, 2014	732,675,143	$ 283,861	49,920,772	111,293,233	586,051,751	(14,874,474)
Balance (in shares) at Dec. 31, 2014		28,386,015
Offering costs	(83,651)	$ 0	0	0	(83,651)	0
Repurchase of common stock	(1,671,479)	$ (1,267)	0	0	(1,670,212)	0
Repurchase of common stock (in shares)		(126,715)
Grant of restricted stock and amortization of equity based compensation	284,376	$ 269	0	0	284,107	0
Grant of restricted stock and amortization of equity based compensation (in shares)		26,910
Common dividends declared	(64,608,797)	$ 0	0	0	0	(64,608,797)
Preferred Series A dividends declared	(4,269,416)	0	0	0	0	(4,269,416)
Preferred Series B dividends declared	(9,200,000)	0	0	0	0	(9,200,000)
Net Income/(Loss)	13,818,537	0	0	0	0	13,818,537
Balance at Dec. 31, 2015	$ 666,944,713	$ 282,863	$ 49,920,772	$ 111,293,233	$ 584,581,995	$ (79,134,150)
Balance (in shares) at Dec. 31, 2015		28,286,210