Intangible Assets and Liabilities - Summary of Intangible Assets and Liabilities (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2017	Dec. 31, 2016
Assets:
Gross	$ 533,844	$ 534,108
Accumulated amortization	(266,758)	(256,305)
Total	$ 267,086	$ 277,803
Weighted Average Remaining Amortization in Years	16 years 4 months 24 days	16 years 1 month 6 days
Liabilities:
Gross	$ 45,713	$ 46,002
Accumulated amortization	(9,704)	(8,946)
Total	$ 36,009	$ 37,056
Weighted Average Remaining Amortization in Years	29 years	28 years 6 months
Below market leases
Liabilities:
Gross	$ 34,081	$ 34,370
Weighted Average Remaining Amortization in Years	19 years	18 years 7 months 6 days
Above market leasehold interests
Liabilities:
Gross	$ 11,632	$ 11,632
Weighted Average Remaining Amortization in Years	52 years 9 months 18 days	53 years
In place leases
Assets:
Gross	$ 296,018	$ 294,597
Weighted Average Remaining Amortization in Years	9 years 10 months 24 days	9 years 8 months 12 days
Tenant relationships
Assets:
Gross	$ 171,541	$ 172,974
Weighted Average Remaining Amortization in Years	10 years 7 months 6 days	10 years 7 months 6 days
Above market leases
Assets:
Gross	$ 28,149	$ 28,401
Weighted Average Remaining Amortization in Years	6 years 3 months 18 days	6 years 3 months 18 days
Below market leasehold interests
Assets:
Gross	$ 38,136	$ 38,136
Weighted Average Remaining Amortization in Years	60 years 3 months 18 days	60 years 4 months 24 days