Real Estate Investments Pro Forma (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Earnings per common share from continuing operations:
Income (loss) from continuing operations attributable to common shareholders, Basic (USD per share)	$ 0.01	$ 0.00	$ 0.04	$ (0.03)
Income (loss) from continuing operations attributable to common shareholders, Dilued (USD per share)	0.01	0.00	0.04	(0.03)
Earnings per common share:
Basic -- as reported (USD per share)	0.01	0.00	0.04	(0.02)
Diluted -- as reported (USD per share)	$ 0.01	$ 0.00	$ 0.04	$ (0.02)
Pro Forma Properties [Member]
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Pro forma revenue	$ 148,677.0	$ 153,893.0	$ 302,323.0	$ 309,771.0
Pro forma income from continuing operations	5,210.0	3,767.0	16,277.0	4,391.0
Pro forma net income available to common shareholders	$ 3,407.0	$ 2,907.0	$ 12,590.0	$ 1,727.0
Earnings per common share from continuing operations:
Income (loss) from continuing operations attributable to common shareholders, Basic (USD per share)	$ 0.01	$ 0.01	$ 0.06	$ (0.01)
Basic -- as pro forma (USD per share)	0.03	0.02	0.09	0.03
Income (loss) from continuing operations attributable to common shareholders, Dilued (USD per share)	0.01	0.01	0.06	(0.01)
Diluted -- as pro forma (USD per share)	0.03	0.02	0.09	0.03
Earnings per common share:
Basic -- as reported (USD per share)	0.00	0.00	0.04	(0.02)
Basic -- as pro forma (USD per share)	0.02	0.02	0.07	0.01
Diluted -- as reported (USD per share)	0.00	0.00	0.04	(0.02)
Diluted -- as pro forma (USD per share)	$ 0.02	$ 0.02	$ 0.07	$ 0.01
Total revenues	$ 3.2	$ 3.4	$ 6.5	$ 7.2
Net income attributable to common shareholders	$ 2.7	$ 2.5	$ 5.1	$ 5.4