Supplemental Cash Flow Information - Schedule of Supplemental Cash Flow Disclosures (Details) - USD ($)
|
12 Months Ended |
Dec. 31, 2017 |
Dec. 31, 2016 |
Dec. 31, 2015 |
| Other Significant Noncash Transactions [Line Items] |
|
|
|
| Reduction and assumption of debt through sale of certain real estate properties |
$ 39,141,000
|
$ 7,208,000
|
$ 30,555,000
|
| Financing provided in connection with disposition of assets |
24,015,000
|
0
|
0
|
| Net real estate and other collateral assets surrendered to lender |
38,547,000
|
30,381,000
|
7,384,000
|
| Reduction of debt in exchange for collateral assets |
0
|
47,025,000
|
7,904,000
|
| Real estate acquired in exchange for loans receivable |
0
|
26,609,000
|
0
|
| Reclass of residual value on expired deferred financing lease to operating asset |
11,088,000
|
0
|
0
|
| Accrued interest capitalized to principal |
3,839,000
|
4,332,000
|
6,035,000
|
| Distributions declared and unpaid |
80,792,000
|
87,055,000
|
76,940,000
|
| Supplemental Cash Flow Disclosures: |
|
|
|
| Cash paid for interest |
163,623,000
|
182,105,000
|
206,115,000
|
| Cash paid for taxes |
911,000
|
914,000
|
1,919,000
|
| Performance Shares |
|
|
|
| Other Significant Noncash Transactions [Line Items] |
|
|
|
| Accrued performance share dividend rights |
$ 817,000
|
$ 489,000
|
$ 564,000
|