Income Taxes (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014
Operating Loss Carryforwards [Line Items]
Distribution % of annual taxable income to stockholders	90.00%
Disqualification of REIT status	4 years
Internal Revenue Service (IRS) [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	534.8
Taxable REIT Subsidiaries [Member] | Internal Revenue Service (IRS) [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	278.0