Mortgage and Other Notes Receivable (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended			6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended					6 Months Ended	12 Months Ended	6 Months Ended		6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended
	Jun. 30, 2014	Dec. 31, 2013	Jun. 30, 2014 Other Entities [Member] Minimum [Member]	Dec. 31, 2013 Other Entities [Member] Minimum [Member]	Jun. 30, 2014 Other Entities [Member] Maximum [Member]	Dec. 31, 2013 Other Entities [Member] Maximum [Member]	Jun. 30, 2014 Mortgages [Member]	Dec. 31, 2013 Mortgages [Member]	Jun. 30, 2014 Mortgages [Member] Coastal Grand - MyrtleBeach [Member]	Dec. 31, 2013 Mortgages [Member] Coastal Grand - MyrtleBeach [Member]	Jun. 30, 2014 Mortgages [Member] One Park Place [Member]	Dec. 31, 2013 Mortgages [Member] One Park Place [Member]	Jun. 30, 2014 Mortgages [Member] Village Square, Houghton Lake and Cadillac [Member]	Dec. 31, 2013 Mortgages [Member] Village Square, Houghton Lake and Cadillac [Member]	Jun. 30, 2014 Mortgages [Member] Other Entities [Member]	Dec. 31, 2013 Mortgages [Member] Other Entities [Member]	Jun. 30, 2014 Other Notes Receivable [Member]	Dec. 31, 2013 Other Notes Receivable [Member]	Jun. 30, 2014 Other Notes Receivable [Member] Outlet Shoppes at Atlanta LLC [Member]	Dec. 31, 2013 Other Notes Receivable [Member] Outlet Shoppes at Atlanta LLC [Member]	Jun. 30, 2014 Other Notes Receivable [Member] Lakeshore Mall [Member]	Jun. 30, 2013 Other Notes Receivable [Member] Lakeshore Mall [Member]	Jun. 30, 2014 Other Notes Receivable [Member] Lees Summit Land [Member]	Dec. 31, 2013 Other Notes Receivable [Member] Lees Summit Land [Member]	Jun. 30, 2014 Other Notes Receivable [Member] Woodstock GA Investments LLC [Member]	Dec. 31, 2013 Other Notes Receivable [Member] Woodstock GA Investments LLC [Member]
Mortgage and Other Notes Receivable [Line Items]
Percentage of assignment of the partnership interest	100.00%
Interest Rate, mortgage loans on real estate			2.65%	2.67%	9.50%	9.50%			7.75%	7.75%	5.00%	5.00%	4.50%	4.50%
Mortgage and other notes receivable	$ 40,137	$ 30,424					$ 18,950	$ 19,120	$ 9,000	$ 9,000	$ 1,653	$ 1,738	$ 2,600	$ 2,600	$ 5,697	$ 5,782	$ 21,187	$ 11,304	$ 699	$ 816	$ 10,000	$ 0	$ 7,429	$ 7,429	$ 3,059	$ 3,059
Interest Rate, other notes receivable																			7.00%	7.00%	5.00%		5.00%	5.00%	10.00%	10.00%