Real Estate (Dispositions) (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended		9 Months Ended
	Dec. 31, 2015	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Income from sales of real estate		$ 34,444	$ 26,511	$ 88,387	$ 66,021
Net proceeds from sales of real estate				412,335	281,346
Payments for repurchase of redeemable noncontrolling interest	$ 6,400
Residential Condominiums
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from sale of other real estate				74,900	113,400
Income from sales of real estate				23,300	36,800
Net Lease Asset Two
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Income from sales of real estate				15,900	15,600
Net proceeds from sales of real estate				108,500	39,400
Commercial Operating Properties
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Income from sales of real estate				49,200
Net proceeds from sales of real estate				229,100
Operating Properties
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net proceeds from sales of real estate					$ 93,500
Initial term of ground lease					99 years
Lease incentive asset	$ 38,100	$ 38,100		$ 38,100
Deferred gain on sale of property			$ 5,300		$ 5,300
RCC [Member] [Member] | Operating Properties
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Income from sales of real estate					13,600
Sales price of real estate held for investment					$ 68,500
Equity interest percentage			50.00%		50.00%