Investments - Summary of Total Impairment Losses Recognized (Details) - USD ($)
$ in Thousands
3 Months Ended 9 Months Ended
Sep. 30, 2016
Sep. 30, 2015
Sep. 30, 2016
Sep. 30, 2015
Investments in and Advances to Affiliates, Schedule of Investments [Abstract]        
Real estate and intangible asset impairment $ 13,894 $ 19,919 $ 35,236 $ 55,273
Write-off of lease intangibles, net 1,491 713 6,463 1,268
Loans receivable impairment (recovery) 0 338 (324) 338
Total impairments from real estate investment net assets 15,385 20,970 41,375 56,879
Other impairment 22 57 21 153
Total impairment loss in continuing and discontinued operations $ 15,407 $ 21,027 $ 41,396 $ 57,032