Notes and Bonds Payable (Details 4) (Senior Notes Due 2021 [Member], USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Senior Notes Due 2021 [Member]
Reconciliation of Senior Notes due 2021
Mortgage notes	$ 400,000	$ 400,000
Unaccreted discount	(2,948)	(3,188)
Senior Notes, carrying amount	$ 397,052	$ 396,812

The amount of debt discount that was originally recognized at the issuance of the instrument that has yet to be amortized.

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