Income Taxes (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Operating Loss Carryforwards [Line Items]
REIT distribution requirement (as a percent)	90.00%	90.00%	90.00%
Tax Cuts and Jobs Act of 2017, income tax expense (Benefit)			$ (64,500,000)
Increase (decrease) in net deferred tax liability	$ (51,900,000)	$ (44,800,000)	(66,500,000)
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount	$ (57,700,000)
Period in which assets disposition subject to built in gains tax	5 years
Net operating loss carryforward related to TRS entities	$ 858,600,000	910,700,000	973,400,000
Difference in bases for entity not subject to income taxes	3,500,000,000	3,800,000,000
Unrecognized tax benefits, income tax penalties and interest accrued	0
Taxable Reit Subsidiaries
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards, valuation allowance	21,200,000	55,100,000	67,100,000
Tax credit carryforward	12,600,000
Net Operating Losses more likely than not to be realized [Member]
Operating Loss Carryforwards [Line Items]
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount	$ (57,700,000)
Interest Expense Limitation due to Tax Cuts and Jobs Act of 2017
Operating Loss Carryforwards [Line Items]
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount		$ (23,200,000)	$ 23,300,000