Investments - Summary of Total Impairment Losses Recognized (Details) - USD ($) $ in Thousands |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2015 |
Jun. 30, 2014 |
Jun. 30, 2015 |
Jun. 30, 2014 |
|
| Investments in and Advances to Affiliates, Schedule of Investments [Abstract] | ||||
| Real estate and intangible asset impairment | $ 33,730 | $ 24,610 | $ 34,773 | $ 26,247 |
| Write-off of lease intangibles due to lease terminations, net | 43 | 2,529 | 555 | 2,599 |
| Total impairments from real estate investment net assets | 33,773 | 27,139 | 35,328 | 28,846 |
| Other impairment | (7) | 488 | 96 | 488 |
| Total impairment loss in continuing and discontinued operations | $ 33,766 | $ 27,627 | $ 35,424 | $ 29,334 |