Equity (Details Textual) (USD $) Share data in Millions, except Per Share data, unless otherwise specified	0 Months Ended	12 Months Ended					1 Months Ended		1 Months Ended
	Feb. 09, 2012	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012 Board Of Directors [Member]	Dec. 31, 2012 Parent Company [Member]	Dec. 31, 2012 Other Partners [Member]	Feb. 29, 2012 8% Series A Cumulative Redeemable Preferred Stock [Member]	Feb. 09, 2012 8% Series A Cumulative Redeemable Preferred Stock [Member]	Jul. 31, 2012 Ipo [Member]	Jul. 31, 2012 Underwriters Option [Member]
Preferred Stock Underwritten Public Offerings								2.3
Preferred Stock, Dividend Rate, Percentage		8.00%	8.00%				8.00%
Stock Issued During Period, Shares, New Issues							0.3		7.5	1.0
Preferred Stock Public Offering Price								$ 25.00
Operating Partnership Units Outstanding		39.0			38.6	0.4
Percentage Of Operating Partnership Units Held					98.90%	1.10%
Fair Market Value Of Operating Partnership Units						$ 5,300,000
Per Unit Fair Market Value Of Operating Partnership Units						$ 12.26
Dividend Declared Per Common Share and Operating Partnership Unit		$ 0.64	$ 0.64	$ 0.16
Accrued Dividends Common Stock		6,200,000
Dividend Declared Per Preferred Share		$ 0.50
Accrued Dividends Preferred Stock		1,000,000
Issuance of preferred stock	54,870,000
Repayments of Long-term Debt	48,900,000
Proceeds from Issuance Initial Public Offering									72,200,000
Dividends paid to common and preferred stockholders		$ 22,300,000	$ 19,600,000
Preferred stock, liquidation preference per share		$ 25.00	$ 25.00				$ 25.00
Preferred Stock, Dividend Rate, Per-Dollar-Amount							$ 2.00
Preferred Stock, Redemption Price Per Share							$ 25.00