Investments - Summary of Gross Real Estate and Loan Activity (Details)
$ in Thousands |
12 Months Ended |
|
Dec. 31, 2017
USD ($)
Property
|
Dec. 31, 2016
USD ($)
Property
|
| Number of Properties |
|
|
| Beginning balance (in properties) | Property |
2,615
|
2,629
|
| Acquisitions/improvements (in properties) | Property |
59
|
269
|
| Dispositions of real estate (in properties) | Property |
(192)
|
(213)
|
| Principal payments and payoffs (in properties) | Property |
(2)
|
(70)
|
| Impairments (in properties) | Property |
0
|
0
|
| Write-off of gross lease intangibles (in properties) | Property |
0
|
0
|
| Loan premium amortization and other (in properties) | Property |
0
|
0
|
| Ending balance (in properties) | Property |
2,480
|
2,615
|
| Dollar Amount of Investments |
|
|
| Beginning balance |
$ 8,247,654
|
$ 8,302,688
|
| Acquisitions/improvements |
350,066
|
711,510
|
| Dispositions of real estate |
(510,863)
|
(598,662)
|
| Principal payments and payoffs |
(7,878)
|
(34,955)
|
| Impairments |
(102,330)
|
(88,249)
|
| Write-off of gross lease intangibles |
(67,139)
|
(42,307)
|
| Loan premium amortization and other |
(6,485)
|
(2,371)
|
| Ending balance |
7,903,025
|
$ 8,247,654
|
| Accumulated depreciation and amortization |
(1,289,304)
|
|
| Other |
304
|
|
| Net balance, December 31, 2017 |
$ 6,614,025
|
|
| Owned Properties |
|
|
| Number of Properties |
|
|
| Beginning balance (in properties) | Property |
2,541
|
2,485
|
| Acquisitions/improvements (in properties) | Property |
43
|
269
|
| Dispositions of real estate (in properties) | Property |
(192)
|
(213)
|
| Principal payments and payoffs (in properties) | Property |
0
|
0
|
| Impairments (in properties) | Property |
0
|
0
|
| Write-off of gross lease intangibles (in properties) | Property |
0
|
0
|
| Loan premium amortization and other (in properties) | Property |
0
|
0
|
| Ending balance (in properties) | Property |
2,392
|
2,541
|
| Dollar Amount of Investments |
|
|
| Beginning balance |
$ 8,181,076
|
$ 8,198,685
|
| Acquisitions/improvements |
326,766
|
711,510
|
| Dispositions of real estate |
(510,863)
|
(598,662)
|
| Principal payments and payoffs |
0
|
0
|
| Impairments |
(101,941)
|
(88,073)
|
| Write-off of gross lease intangibles |
(67,139)
|
(42,307)
|
| Loan premium amortization and other |
(4,841)
|
(77)
|
| Ending balance |
7,823,058
|
$ 8,181,076
|
| Accumulated depreciation and amortization |
(1,289,304)
|
|
| Other |
304
|
|
| Net balance, December 31, 2017 |
$ 6,534,058
|
|
| Financed Properties |
|
|
| Number of Properties |
|
|
| Beginning balance (in properties) | Property |
74
|
144
|
| Acquisitions/improvements (in properties) | Property |
16
|
0
|
| Dispositions of real estate (in properties) | Property |
0
|
0
|
| Principal payments and payoffs (in properties) | Property |
(2)
|
(70)
|
| Impairments (in properties) | Property |
0
|
0
|
| Write-off of gross lease intangibles (in properties) | Property |
0
|
0
|
| Loan premium amortization and other (in properties) | Property |
0
|
0
|
| Ending balance (in properties) | Property |
88
|
74
|
| Dollar Amount of Investments |
|
|
| Beginning balance |
$ 66,578
|
$ 104,003
|
| Acquisitions/improvements |
23,300
|
0
|
| Dispositions of real estate |
0
|
0
|
| Principal payments and payoffs |
(7,878)
|
(34,955)
|
| Impairments |
(389)
|
(176)
|
| Write-off of gross lease intangibles |
0
|
0
|
| Loan premium amortization and other |
(1,644)
|
(2,294)
|
| Ending balance |
79,967
|
$ 66,578
|
| Accumulated depreciation and amortization |
0
|
|
| Other |
0
|
|
| Net balance, December 31, 2017 |
$ 79,967
|
|