Schedule III (Consolidated) - Real Estate and Accumulated Depreciation - Reconciliation of Accumulated Depreciation (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Balance at beginning of the year	$ 53,496	$ 49,772	$ 44,489
Depreciation expense	6,170	6,547	7,494
Amounts retired or adjusted	(1,534)	(2,823)	(2,211)
Balance at the end of the year	$ 58,132	$ 53,496	$ 49,772