Other Assets - Schedule of Other Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Other Assets [Abstract]
Straight-line rent receivables, net of allowance of $24,737 and $25,059, respectively	$ 320,485	$ 311,776
Marketable debt securities, net	18,448	68,630
Leasing costs and inducements, net	91,818	156,820
Goodwill	47,019	42,386
Other	133,920	132,012
Total other assets, net	611,690	711,624
Allowance on straight-line rent receivables	$ 24,737	$ 25,059