SCHEDULE III - REAL ESTATE AND ACCUMULATED DEPRECIATION Reconciliation of Accumulated Depreciation (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Balance at beginning of year	$ 160,541	$ 143,232	$ 124,562
Depreciation related to real estate	26,488	17,309	18,670
Balance at end of year	$ 187,029	$ 160,541	$ 143,232