Equity - 6.25% Series A Cumulative Redeemable Preferred Units of the Operating Partnership Narrative (Details) - 6.25% series A cumulative redeemable preferred units of the Operating Partnership - $ / shares	6 Months Ended	12 Months Ended
Jun. 30, 2015	Dec. 31, 2014
Class of Stock
Shares outstanding of preferred stock	407,066
Interest rate of preferred stock	6.25%	6.25%
Liquidation preference of preferred stock (dollars per share)	$ 25

Equity - 6.25% Series A Cumulative Redeemable Preferred Units of the Operating Partnership Narrative (Details) - 6.25% series A cumulative redeemable preferred units of the Operating Partnership - $ / shares

6 Months Ended

12 Months Ended

Jun. 30, 2015

Dec. 31, 2014

Class of Stock

Shares outstanding of preferred stock

407,066

Interest rate of preferred stock

6.25%

Liquidation preference of preferred stock (dollars per share)

$ 25