Subsequent Events (Details Textual) - Range [Domain] - USD ($) $ in Thousands		1 Months Ended			3 Months Ended	12 Months Ended
		Jun. 15, 2015	May. 21, 2015	Apr. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Jun. 25, 2015	May. 03, 2015	May. 02, 2015	Mar. 24, 2015	Jan. 31, 2013
Payments to Acquire Businesses, Gross					$ 7,700
Debt Instrument, Interest Rate During Period						1.30%
Long-Term Line Of Credit	[1]				263,500	$ 217,500
Loans Payable											$ 50,000
Revolving Credit Facility [Member]
Long-Term Line Of Credit					213,500
Unsecured Debt											$ 250,000
Subsequent Event [Member]
Equity Method Investment, Ownership Percentage							0.00%
Fair Value Of Non Controlling Interest				$ 4,600
Debt Instrument, Debt Default, Description of Notice of Default			The Notice further provided that, pursuant to Section 6.01(b) of the Indenture, the Operating Partnership elected that the sole remedy for the reporting event of default would consist exclusively of the right to receive additional interest on the Exchangeable Senior Notes at a rate equal to (i) 0.25% per annum of the outstanding principal amount of the Exchangeable Senior Notes for the first 90 days of the 180-day period in which such reporting event of default is continuing, beginning on, and including, the date on which such reporting event of default first occurs and (ii) 0.50% per annum of the outstanding principal amount of the Exchangeable Senior Notes for the last 90 days of such 180-day period as long as such reporting event of default is continuing, payable subject to and in accordance with the terms and conditions of the Indenture.
Modification Fees										$ 100
Indemnity Receivable					4,000
Fair Value Of Guarantees					4,000
Restricted Cash and Cash Equivalents									$ 5,000
Subsequent Event [Member] | Copper Beech Transaction [Member]
Equity Method Investment, Ownership Percentage				48.00%
Cash paid to Sellers				$ 1,400
Operating Partnership Issued To The Sellers				2,000
Subsequent Event [Member] | Penn State Seller [Member]
Payments to Acquire Businesses, Gross				2,300
Equity Method Investment, Aggregate Cost				4,600
Equity Method Investment Unpaid Balance				$ 2,300
Subsequent Event [Member] | Penn State Seller [Member] | Copper Beech Klondike [Member]
Noncontrolling Interest, Ownership Percentage by Parent				15.00%
Subsequent Event [Member] | Penn State Seller [Member] | Copper Beech Northbrook [Member]
Noncontrolling Interest, Ownership Percentage by Parent				16.00%
Subsequent Event [Member] | Clinton Group [Member]
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners								1.60%
Subsequent Event [Member] | CBTC 23 [Member]
Long-Term Line Of Credit					1,000
Indemnity Receivable					$ 4,000
Subsequent Event [Member] | San Angelo Sale [Member]
Sale Of Ownership Interest Percentage		100.00%
Subsequent Event [Member] | Senior Notes [Member]
Debt Instrument, Interest Rate During Period			4.75%

[1] As stated in Note 6, on January 30, 2015, the Company and certain of its affiliates completed the acquisition of substantially all of the Sellers’ remaining interests in most of the Copper Beech properties. This acquisition represents $220.5 million of the increase in the fixed-rate mortgage loans, $37.9 million of the increase in the construction loans and $4.5 million of the increase in other debt related to Copper Beech letters of credit.