Equity (Details Textual) - USD ($)		12 Months Ended
	Sep. 06, 2012	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Nov. 03, 2015	Jul. 13, 2012
Class of Stock [Line Items]
Capital Available For Issuance		$ 750,000,000				$ 1,000,000,000
Payments for Repurchase of Common Stock		9,928,615	$ 472,892	$ 0
Stock Repurchase Program, Authorized Amount		25,000,000			$ 25,000,000
Repurchase [Member]
Class of Stock [Line Items]
Payments for Repurchase of Common Stock		$ 614,695	$ 126,715
Shares Issued, Price Per Share		$ 14.20	$ 13.19
Treasury Stock, Value, Acquired, Cost Method		$ 8,700,000	$ 1,700,000
Stock Repurchase Program, Remaining Number of Shares Authorized to be Repurchased		14,600,000
Sale Agents [Member]
Class of Stock [Line Items]
Stock Issued During Period Shares New Issues	3,000,000	1,254,854
Proceeds From Issuance Of Common Stock Net		$ 31,300,000
Series A Preferred Stock [Member]
Class of Stock [Line Items]
Preferred Stock, Liquidation Preference, Value (in dollars per share)		$ 25.00
Dividend		8.25%
Series B Preferred Stock [Member]
Class of Stock [Line Items]
Preferred Stock, Liquidation Preference, Value (in dollars per share)		$ 25.00
Dividend		8.00%
Private Placement [Member]
Class of Stock [Line Items]
Sale of Stock, Price Per Share		$ 20.00
Sale of Stock, Number of Shares Issued in Transaction		3,205,000
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right		0.5
Class of Warrant or Right, Exercise Price of Warrants or Rights		$ 20.50