Subsequent Events (Details)			1 Months Ended	6 Months Ended
	Jul. 01, 2015 USD ($) property item $ / shares	Jun. 30, 2015 USD ($) property item	Apr. 30, 2015 USD ($)	Jun. 30, 2015 USD ($) property item	Jun. 30, 2014 USD ($)	Dec. 31, 2014 USD ($)
Real Estate Investments
Number of properties acquired | property				1
Number of beds/units acquired | item				106
Purchase Price				$ 24,957,000
Debt Obligations
Amount outstanding		$ 357,967,000		357,967,000		$ 281,633,000
Private Shelf Agreement Prudential
Debt Obligations
Debt instrument term			3 years
Maximum available for issuance			$ 200,000,000
Subsequent Event [Member] | Dividend Declared [Member]
Equity
Cash dividend declared per common share per month (in dollars per share) | $ / shares	$ 0.17
Subsequent Event [Member] | Private Shelf Agreement Prudential
Debt Obligations
Face amount of debt	$ 100,000,000
Fixed interest rate (as a percent)	4.50%
Subsequent Event [Member] | Note Purchase and Private Shelf Agreement AIG [Member]
Debt Obligations
Debt instrument term	3 years
Maximum available for issuance	$ 100,000,000
Bank Borrowings - Line of Credit [Member]
Debt Obligations
Amount borrowed				82,000,000	$ 21,000,000
Repayments of debt				1,500,000
Amount outstanding		80,500,000		80,500,000
Remaining borrowing capacity		319,500,000		319,500,000		400,000,000
Bank Borrowings - Line of Credit [Member] | Subsequent Event [Member]
Debt Obligations
Amount borrowed	24,000,000
Amount outstanding	104,500,000
Remaining borrowing capacity	295,500,000
Senior Unsecured Debt [Member]
Debt Obligations
Repayments of debt	25,000,000			4,167,000	4,167,000
Amount outstanding	252,467,000	$ 277,467,000		$ 277,467,000		$ 281,633,000
Senior Unsecured Debt [Member] | Subsequent Event [Member]
Debt Obligations
Repayments of debt	25,000,000
Amount outstanding	252,467,000
Senior Unsecured Debt [Member] | Subsequent Event [Member] | Private Shelf Agreement Prudential
Debt Obligations
Face amount of debt	$ 100,000,000
Fixed interest rate (as a percent)	4.50%
Debt instrument term	15 years
Bonds [Member]
Debt Obligations
Repayments of debt					$ 635,000
Portfolio of 10 Properties [Member] | Scenario, Forecast [Member]
Real Estate Investments
Number of properties acquired | property		10
Number of beds/units acquired | item		891
Purchase Price		$ 142,000,000
Portfolio of 10 Properties [Member] | Subsequent Event [Member] | Scenario, Forecast [Member]
Real Estate Investments
Number of properties acquired | property	10
Number of beds/units acquired | item	891
Purchase Price	$ 142,000,000