Other Assets - Schedule of Other Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Other Assets [Abstract]
Straight-line rent receivables, net of allowance of $22,705 and $25,059, respectively	$ 313,627	$ 311,776
Leasing costs and inducements, net	102,557	156,820
Deferred tax assets	60,254	42,458
Goodwill	47,019	42,386
Marketable debt securities, net	18,567	68,630
Other	74,145	89,554
Total other assets, net	616,169	711,624
Allowance on straight-line rent receivables	$ 22,705	$ 25,059