Real Estate (Dispositions) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2013 properties		Sep. 30, 2012 properties		Sep. 30, 2013 properties	Sep. 30, 2012 properties
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of sold properties	22		8		31	18
Gain (loss) on disposition of assets, discontinued operations	$ 1,228		$ 1,694		$ 4,402	$ 4,446
Gain (loss) on disposition of assets noncontrolling interest portion discontinued operations	0		0		153	0
Assets Held-for-sale [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain (loss) on disposition of assets, discontinued operations	$ 1,228	[1]	$ 1,694	[1]	$ 4,249	$ 4,446	[1]

[1] None of the gains from property sales for the period were reported in continuing operations.