Discontinued Operations (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Discontinued operations [Abstract]
Rental and other revenues	$ 0	$ 6,998
Operating expenses:
Rental property and other expenses	0	2,450
Depreciation and amortization	0	2,204
Total operating expenses	0	4,654
Income from discontinued operations	0	2,344
Impairments of real estate assets	0	(1,128)
Net gains on disposition of discontinued operations	384	1,244
Total discontinued operations	$ 384	$ 2,460