Transactions with Related Parties (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Related Party Transaction [Line Items]
rate for administration fees	0.45%
Affiliated Entity [Member]
Related Party Transaction [Line Items]
Administrative Fees, Amount Paid	$ 133,000	$ 160,000	$ 209,000
Majority-Owned Subsidiary, Unconsolidated [Member]
Related Party Transaction [Line Items]
Administrative Fees, Amount Paid	948,000	795,000	636,000
Ohio Properties [Member] | Affiliated Entity [Member]
Related Party Transaction [Line Items]
Administrative Fees, Amount Paid			231,000
Eagle Ridge [Member] | Affiliated Entity [Member]
Related Party Transaction [Line Items]
Administrative Fees, Amount Paid	$ 71,000