Real Estate (Dispositions) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2015 USD ($) property	Dec. 31, 2014 USD ($) property	Dec. 31, 2013 USD ($) property
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Income tax expense	$ (10,318)	$ 75	$ (74)
Discontinued operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain on disposition of real estate	0	155	6,272
Income tax expense	0	$ 0	$ (784)
Gain on disposition of real estate, net of income tax expense	$ 10,450
Number of sold properties | property	0	2	35
Gain on disposition of assets, total, continuing and discontinued operations	$ 10,450	$ 11,424	$ 5,595
Assets Held-for-sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of sold properties | property	19	25	0
Gain on disposition of real estate	$ 10,807	$ 11,587	$ 173
Income tax expense	$ (357)	(318)	(66)
Gain on disposition of real estate, net of income tax expense		$ 11,269	$ 107
Assets Held-for-sale | Discontinued operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of sold properties | property	5