Property Dispositions (Narrative) (Details) $ in Thousands		6 Months Ended		12 Months Ended
		Jun. 30, 2015 USD ($) property	Jun. 30, 2014 USD ($) property	Dec. 31, 2014 USD ($) property
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of real estate properties foreclosed upon | property		1
Foreclosed upon property net book value		$ 16,151,287		$ 17,258,438
Number of properties classified held for sale | property		2		2
Goodwill allocated to dispositions	[1]	$ 47,499		$ 210,139
Property Dispositions, 2015 [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Aggregate gross sales price		352,300
Disposition costs and purchase price adjustments		3,300
Net loss on sale of properties		23,200
Goodwill allocated to dispositions		17,800
Foreclosed Upon Real Estate Property [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Foreclosed upon property net book value		$ 38,200
Property Dispositions, 2014 [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Aggregate gross sales price			$ 96,400
Single Family [Member] | Property Dispositions, 2015 [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of real estate properties disposed of (in number of single-tenant properties and multi-tenant properties) | property		11
Single Family [Member] | Property Dispositions, 2014 [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of real estate properties disposed of (in number of single-tenant properties and multi-tenant properties) | property			24
Multifamily [Member] | Property Dispositions, 2015 [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of real estate properties disposed of (in number of single-tenant properties and multi-tenant properties) | property		3
Multifamily [Member] | Property Dispositions, 2014 [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of real estate properties disposed of (in number of single-tenant properties and multi-tenant properties) | property			1
Consolidated Joint Venture [Member] | Property Dispositions, 2015 [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of real estate properties disposed of (in number of single-tenant properties and multi-tenant properties) | property		1

[1] Goodwill allocated to the cost basis of properties sold or held for sale and included in loss on disposition of real estate and held for sale assets, net, in the consolidated statements of operations.