Investments in Real Estate - Purchase Price Allocation (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Asset Acquisition
Land	$ 108,709	$ 1,895	$ 100,922
Building and improvements	396,660	14,458	2,358,771
In place leases	51,629	1,237	190,020
Below market leases	(5,187)	(201)	(27,849)
Above market leases	3,487	0	12,180
Below market leasehold interests	0	0	54,252
Above market leasehold interests	0	0	(8,978)
Net assets acquired	555,298	17,389	2,679,318
Other, net	5,158	447	60,913
Aggregate purchase price	$ 560,456	$ 17,836	$ 2,740,231