Intangible Assets Intangible Assets, Schedule of Finite-Lived Intangible Assets (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 135,104	$ 133,385
Accumulated Amortization	(44,893)	(33,551)
Ground Leases [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	33,270	33,270
Accumulated Amortization	$ (1,371)	(600)
Leases, Acquired-in-Place [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	7 years
Gross Carrying Amount	$ 99,954	98,235
Accumulated Amortization	$ (42,090)	(31,796)
Franchise Rights [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	15 years
Gross Carrying Amount	$ 1,880	1,880
Accumulated Amortization	$ (1,432)	$ (1,155)
Minimum [Member] | Ground Leases [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	8 years
Maximum [Member] | Ground Leases [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	57 years