Lease Intangibles - Schedule of Intangible Assets and Liabilities (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Dec. 31, 2016
Amortizable Intangible Assets
Amortizable Intangible Assets, Gross Carrying Amount	$ 191,441	$ 173,069
Amortizable Intangible Assets, Accumulated Amortization	(72,439)	(58,485)
Amortizable Intangible Assets, Net Carrying Amount	119,002	114,584
Amortizable Intangible Liabilities
Amortizable Intangible Liabilities, Gross Carrying Amount	(141,157)	(137,032)
Amortizable Intangible Liabilities, Accumulated Amortization	37,844	32,004
Amortizable Intangible Liabilities, Net Carrying Amount	(103,313)	(105,028)
Above-market Ground Lease, Gross	(672)	0
Above-market Ground Lease, Accumulated Amortization	5	0
Above-market Ground Lease, Net	(667)	0
Finite-Lived Intangible Liabilities, Gross	(141,829)	(137,032)
Finite-Lived Intangible Liabilities, Accumulated Amortization	37,849	32,004
Finite-Lived Intangible Liabilities, Net	(103,980)	(105,028)
Below market rents, acquired	$ 4,100
Below market rents acquired, weighted average useful life	11 years 5 months
Above-market ground lease, acquired	$ 700
Above-market ground lease acquired, weighted average useful life	11 years 6 months
In-place lease intangible assets
Amortizable Intangible Assets
Amortizable Intangible Assets, Gross Carrying Amount	$ 174,113	156,420
Amortizable Intangible Assets, Accumulated Amortization	(60,712)	(47,827)
Amortizable Intangible Assets, Net Carrying Amount	113,401	108,593
Intangible assets acquired	$ 17,700
Acquired intangible assets, weighted average useful life	4 years 2 months
Above-market rent
Amortizable Intangible Assets
Amortizable Intangible Assets, Gross Carrying Amount	$ 17,328	16,649
Amortizable Intangible Assets, Accumulated Amortization	(11,727)	(10,658)
Amortizable Intangible Assets, Net Carrying Amount	5,601	$ 5,991
Intangible assets acquired	$ 700
Acquired intangible assets, weighted average useful life	3 years 9 months