Investments - Summary of Real Estate and Loan Activity, Net of Accumulated Depreciation and Amortization (Footnote) (Details) $ in Millions |
9 Months Ended | |
|---|---|---|
|
Sep. 30, 2015
USD ($)
Property
|
Dec. 31, 2014
Property
|
|
| Real Estate Properties [Line Items] | ||
| Revenue producing capitalized expenditures | $ 6.7 | |
| Capitalized maintenance expenditures | 0.7 | |
| Accumulated depreciation and amortization associated with dispositions of real estate | $ 86.2 | |
| Number of properties sold under 1031 Exchanges | Property | 26 | |
| Amount of properties sold under 1031 Exchanges | $ 235.4 | |
| Amount of properties acquired under 1031 Exchanges | $ 233.0 | |
| Number of properties acquired under 1031 Exchanges | Property | 97 | |
| Properties Vacant | ||
| Real Estate Properties [Line Items] | ||
| Number of properties | Property | 37 | 37 |
| Property Held For Sale | ||
| Real Estate Properties [Line Items] | ||
| Number of properties | Property | 14 | 8 |