Investments - Summary of Real Estate and Loan Activity, Net of Accumulated Depreciation and Amortization (Footnote) (Details) $ in Millions |
9 Months Ended | |
|---|---|---|
|
Sep. 30, 2016
USD ($)
Property
|
Dec. 31, 2015
Property
|
|
| Real Estate Properties [Line Items] | ||
| Revenue producing capitalized expenditures | $ | $ 5.4 | |
| Capitalized maintenance expenditures | $ | 2.9 | |
| Accumulated depreciation and amortization associated with dispositions of real estate | $ | $ 48.6 | |
| Number of properties sold under 1031 Exchanges | Property | 6 | |
| Amount of properties sold under 1031 Exchanges | $ | $ 43.7 | |
| Amount of properties acquired under 1031 Exchange program using 2015 proceeds | $ | $ 39.9 | |
| Number of properties acquired under 1031 Exchanges | Property | 33 | |
| Properties Vacant | ||
| Real Estate Properties [Line Items] | ||
| Number of properties | Property | 43 | 36 |
| Property Held For Sale | ||
| Real Estate Properties [Line Items] | ||
| Number of properties | Property | 11 | 12 |
| Properties Securing Assets | ||
| Real Estate Properties [Line Items] | ||
| Number of properties | Property | 69 |