Schedule IV - Mortgage Loans on Real Estate (Notes to Schedule IV) (Details) (USD $) In Thousands, unless otherwise specified					12 Months Ended
	Dec. 31, 2011 properties		Dec. 31, 2010 properties	Dec. 31, 2011 Final Payment Date 2014 A [Member] properties	Dec. 31, 2011 Note A [Member] Final Payment Date 2014 A [Member]	Dec. 31, 2011 Note B [Member] Final Payment Date 2014 A [Member]
Number of Real Estate Properties	97		88	8
Mortgage Loans on Real Estate, Face Amount of Mortgages				$ 26,293	$ 16,513	$ 9,780
Mortgage Loans on Real Estate, Carrying Amount of Mortgages	$ 78,672	[1]		$ 21,337	$ 11,557
Mortgage Loans on Real Estate, Interest Rate					8.50%	3.00%

[1] See Note 4 to Consolidated Financial Statements for more information on our mortgage loan receivables.