Real Estate (Dispositions) (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2016 USD ($) property	Mar. 31, 2015 USD ($) property
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Income tax expense	$ 0	$ (442)
Assets Held-for-sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of sold properties - gain on disposition of real estate | property	10	6
Gain on disposition of real estate	$ 16,875	$ 7,230
Income tax expense	0	(30)
Gain on disposition of real estate, net of income tax expense	$ 16,875	$ 7,200