Equity (Details Textual) (USD $)	0 Months Ended	1 Months Ended		0 Months Ended	1 Months Ended		10 Months Ended	12 Months Ended		1 Months Ended	0 Months Ended			1 Months Ended		12 Months Ended				0 Months Ended	1 Months Ended	0 Months Ended				1 Months Ended	0 Months Ended	1 Months Ended					0 Months Ended	1 Months Ended
	Aug. 03, 2012	Dec. 26, 2012	Sep. 27, 2012	Aug. 15, 2012	Jan. 24, 2012	Jul. 20, 2011	Dec. 31, 2011	Dec. 31, 2013	Dec. 31, 2012	Jul. 20, 2011 Underwriters [Member]	Sep. 06, 2012 Sale Agents [Member]	Aug. 03, 2012 8.25% Series A Cumulative Redeemable Preferred Stock [Member]	Aug. 03, 2012 8.25% Series A Cumulative Redeemable Preferred Stock [Member] Underwriters [Member]	Sep. 27, 2012 8.00% Series B Cumulative Redeemable Preferred Stock [Member]	Jun. 29, 2011 Ag Funds [Member]	Dec. 31, 2013 Cash Less Warrants [Member]	Dec. 31, 2012 Cash Less Warrants [Member]	Dec. 31, 2013 Cash Excercise Warrants [Member]	Dec. 31, 2012 Cash Excercise Warrants [Member]	Jul. 06, 2011 Manager Equity Incentive Plan [Member]	Jul. 20, 2011 Manager Equity Incentive Plan [Member]	Jul. 06, 2011 Equity Incentive Plan [Member]	Jul. 06, 2011 Equity Incentive Plan [Member] Director [Member]	Jul. 06, 2011 IPO [Member]	Jul. 06, 2011 After Underwriter Allotment [Member]	Jul. 20, 2011 After Underwriter Allotment [Member]	Jul. 06, 2011 Private Placement [Member]	Jul. 20, 2011 Private Placement [Member]	Jul. 20, 2011 Underwriting Agreement [Member]	Jun. 29, 2011 Underwriting Agreement [Member]	Jul. 20, 2011 Over Allotment Option [Member]	Sep. 27, 2012 Over Allotment Option [Member] 8.00% Series B Cumulative Redeemable Preferred Stock [Member]	Aug. 15, 2012 Underwriters Over-Allotment Option [Member]	Jan. 24, 2012 Underwriters Over-Allotment Option [Member]	Jul. 13, 2012 Underwriters Over-Allotment Option [Member]
Class of Stock [Line Items]
Stock Issued During Period Shares New Issues		3,750,000		6,000,000	5,000,000					800,000	1,254,854	1,800,000	270,000	4,000,000										9,205,000		10,005,000			800,000	5,500,000	825,000	600,000	900,000	750,000
Sale of Stock, Price Per Share		$ 24.33		$ 23.29						$ 20.00			$ 25.00	$ 25.00													$ 20.00		$ 20.00					$ 19.00
Proceeds from issuance of common stock		$ 91,200,000		$ 160,700,000	$ 109,300,000	$ 16,000,000	$ 198,115,606	$ 33,176,288	$ 353,673,174			$ 51,800,000		$ 115,000,000										$ 182,300,000		$ 198,100,000			$ 198,100,000
Offering costs paid					5,300,000																			1,800,000					2,000,000
Proceeds From Issuance Of Common Stock Net		87,500,000		152,700,000	104,000,000			31,300,000				49,900,000		111,300,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period																20,101	60,453	196,250	380,999
Stock Issued During Period, Value, Stock Options Exercised																		4,000,000	7,800,000
Common stock, shares authorized								450,000,000	450,000,000		3,000,000
Preferred Stock, Liquidation Preference, Value (in dollars per share)	$ 25.00		$ 25.00
Capital Available For Issuance								549,500,000																											1,000,000,000
Dividend	8.25%		8.00%
Sale Price Per Stock Under writing Agreement																														$ 20.00
Common Shares Value Authorized By Under Writing Agreement																														110,000,000
Sale Price Per Stock Private Placement															$ 20.00
Stock Issued Private Placement															500,000
Company Obligation To Pay Private Placement Description						1% of the total gross proceeds from the IPO and the concurrent private placement or approximately $2.0 million when the underwriters exercised their overallotment option															1% of the total gross proceeds from the offering and concurrent private placement (or approximately $1.8 million, increasing to approximately $2.0 million when the underwriters exercised their overallotment option).
Stock Issued During Period, Shares, Share-Based Compensation, Net Of Forfeitures																				40,250		1,500	1,500
Stock Issued Per Share On Conversion Of Units																											$ 0.5
Adjustments to Additional Paid in Capital, Warrant Issued																									3,205,000		3,205,000
Class of Warrant or Right, Exercise Price of Warrants or Rights																											20.50
Proceeds from Issuance of Private Placement																												$ 74,100,000