Debt (Details) (USD $) In Thousands, unless otherwise specified	1 Months Ended	12 Months Ended
	Oct. 07, 2011	Dec. 31, 2012	Dec. 31, 2011
Mortgage Loans Payable
Maturity		May 2012
Interest rate, description	LIBOR + 1.25% with a 3% LIBOR floor	LIBOR + 3.75%	LIBOR plus 3.25%
Mortgage loans payable		$ 280,576	$ 230,940
Amherst, NY [Member] | Five Point Six Five Percent Loan Due October Two Thousand And Thirteen [Member]
Mortgage Loans Payable
Maturity		Oct 2013
Interest rate, description
Interest rate		5.65%
Mortgage loans payable		15,225	15,682
Memphis, TN [Member] | Three percent loan due august two thousand and fourteen [Member]
Mortgage Loans Payable
Maturity		Aug-2014
Interest rate, description		Libor + 2.5%
Interest rate		3.00%
Mortgage loans payable		13,408
Chicago, IL [Member] | Six Point Two Five Percent Loan Due April Two Thousand And Fifteen [Member]
Mortgage Loans Payable
Maturity		Apr-2015
Interest rate, description
Interest rate		6.25%
Mortgage loans payable		8,700	8,900
Chicago, IL [Member] | Five Point Seven Five Percent Loan Due March Two Thousand And Sixteen [Member]
Mortgage Loans Payable
Maturity		Mar 2016
Interest rate, description
Interest rate		5.75%
Mortgage loans payable		20,200	20,522
Lisle, IL [Member] | Two Point Seven One Percent Loan Due October Two Thousand And Fourteen [Member]
Mortgage Loans Payable
Maturity		Oct 2014
Interest rate, description		Libor + 2.5 %
Interest rate		2.71%
Mortgage loans payable		5,752	21,000
Lisle, IL [Member] | Five Point Five Five Percent Loans Due March Two Thousand Seventeen [Member]
Mortgage Loans Payable
Maturity		Mar 2017
Interest rate, description
Interest rate		5.55%
Mortgage loans payable		5,543	5,600
Houston, TX [Member] | Six Point One Five Percent Loan Due April Two Thousand And Sixteen [Member]
Mortgage Loans Payable
Maturity		Apr 2016
Interest rate, description
Interest rate		6.15%
Mortgage loans payable		52,052	56,423
New York, NY [Member] | Three Point Five Percent Due May Two Thousand Sixteen [Member]
Mortgage Loans Payable
Maturity		May 2016
Interest rate, description		Libor + 2.5%
Interest rate		3.50%
Mortgage loans payable		51,982	49,585
Greensboro, NC [Member] | Six Point Two Two Percent Loan Due August Two Thousand And Sixteen [Member]
Mortgage Loans Payable
Maturity		Aug-2016
Interest rate, description
Interest rate		6.22%
Mortgage loans payable		15,139
Cerritos, CA [Member] | Five Point Zero Seven Percent Loan Due January Two Thousand And Seventeen [Member]
Mortgage Loans Payable
Maturity		Jan 2017
Interest rate, description
Interest rate		5.07%
Mortgage loans payable		23,184
Orlando, FL [Member] | Six Point Four Zero Percent Loans Due July Two Thousand Seventeen [Member]
Mortgage Loans Payable
Maturity		Jul 2017
Interest rate, description
Interest rate		6.40%
Mortgage loans payable		37,580	38,132
Plantation, FL [Member] | Six Point Four Eight Percent Loans Due April Two Thousand Eighteen [Member]
Mortgage Loans Payable
Maturity		Apr 2018
Interest rate, description
Interest rate		6.48%
Mortgage loans payable		10,811	10,927
Meriden Ct [Member] | Three point nine five percent loan due October two thousand and twenty two [Member]
Mortgage Loans Payable
Maturity		Oct 2022
Interest rate, description
Interest rate		3.95%
Mortgage loans payable		21,000
Indianapolis, IN [Member]
Mortgage Loans Payable
Maturity
Interest rate, description
Interest rate
Mortgage loans payable			$ 4,169