8.0% Exchangeable Senior Notes due 2016 (Details) (USD $)	3 Months Ended													0 Months Ended		3 Months Ended		3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 20, 2014	Dec. 31, 2013	Dec. 19, 2013		Sep. 18, 2013	Jun. 25, 2013	May 14, 2013	Dec. 19, 2013 Special Cash Dividend [Member]	Mar. 31, 2014 Exchangeable Senior Notes Conversion Option [Member]	Dec. 31, 2013 Exchangeable Senior Notes Conversion Option [Member]	Nov. 25, 2013 Exchangeable Senior Notes Conversion Option [Member]	Dec. 27, 2013 Exchangeable Senior Notes [Member]	Nov. 25, 2013 Exchangeable Senior Notes [Member]	Mar. 31, 2014 Exchangeable Senior Notes [Member]	Dec. 31, 2013 Exchangeable Senior Notes [Member]	Mar. 31, 2014 Exchangeable Senior Notes [Member] Maximum [Member]
Debt Instrument [Line Items]
Principal amount																$ 57,500,000
Proceeds from sale of debt															55,300,000
Initial purchasers' discount															1,700,000
Aggregate estimated offering expenses															2,200,000
Carrying value of debt																54,800,000	54,500,000
Stated interest rate																8.00%
Effective annual rate																10.20%
Interest expense on notes	1,412,643															1,400,000
Maturity date																Nov. 15, 2016
Percentage of shares outstanding issuable upon exchange																20.00%
Number of shares issuable upon exchange																1,779,560
Derivative liabilities, at fair value	$ 1,606,416			$ 1,471,607							$ 1,600,000	$ 1,500,000	$ 1,300,000
Conversion ratio														54.3103	52.5417			60.4229
Exchange price															$ 19.03
Dividend threshold requiring adjustment to exchange rate																$ 0.50
Dividend declared, amount per share			$ 0.40		$ 0.95	[1]	$ 0.50	$ 0.45	$ 0.22	$ 0.55
Repurchase price																100.00%

[1] Regular cash dividend of $0.40 per share of common stock and OP unit for the fourth quarter ending December 31, 2013, and an additional special cash dividend of $0.55 per share of its common stock and OP unit. The Company declared the special cash dividend to distribute taxable income from 2013 attributable to the termination of interest rate swap contracts.