Intangibles - Acquired Lease Intangible Amortization (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
In-place leases
Finite-Lived Intangible Assets [Line Items]
Amortization expense related to in-place leases	$ 28,902	$ 15,300	$ 4,133
Above market leases
Finite-Lived Intangible Assets [Line Items]
Decrease of rental income	4,403	2,596	530
Leasehold interest
Finite-Lived Intangible Assets [Line Items]
Decrease of rental income	59	59	5
Below market in-place lease
Finite-Lived Intangible Assets [Line Items]
Increase of rental income	1,835	643	156
Below market in-place ground lease
Finite-Lived Intangible Assets [Line Items]
Decrease (increase) of operating expense	24	16	4
Below Market Ground Lease
Finite-Lived Intangible Assets [Line Items]
Decrease (increase) of operating expense	$ 471	$ 68	$ 0