|
Investments - Narrative (Details) (USD $)
|
12 Months Ended |
|
|
Dec. 31, 2014
loan
borrower
Property
State
|
Dec. 31, 2013
loan
borrower
Property
|
Dec. 31, 2012
Property
|
| Investments in and Advances to Affiliates, Schedule of Investments [Abstract] |
|
|
|
| Real Estate Investment Property At Cost Loan Premium Amortization And Other |
$ 2,840,000 |
$ 2,555,000 |
|
| Investment [Line Items] |
|
|
|
| Real estate properties and loans, gross |
8,044,363,000 |
7,235,732,000 |
3,654,925,000 |
| Real estate assets held for sale |
2,509 |
2,186 |
1,207 |
| Properties dispersed geographically |
49 |
|
|
| Minimum percentage of investment in real estate properties |
10.00% |
|
|
| Number of owned real estate properties |
2,364 |
2,041 |
|
| Securing mortgage properties carrying amount |
109,000,000 |
117,300,000 |
|
| Other loans receivable with aggregate carrying value amounts |
$ 400,000 |
|
|
| Number of first-priority mortgage loans |
79 |
80 |
|
| Number of borrowers |
8 |
9 |
|
| Properties Vacant [Member] |
|
|
|
| Investment [Line Items] |
|
|
|
| Number of properties |
37 |
21 |
|
| Property Held for Sale [Member] |
|
|
|
| Investment [Line Items] |
|
|
|
| Number of properties |
8 |
6 |
|
| Texas [Member] |
|
|
|
| Investment [Line Items] |
|
|
|
| Number of states exceeding disclosure threshold |
1 |
|
|
| Percentage of investment in real estate properties |
12.20% |
|
|