Intangible Assets (Intangibles - Future Amortization) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Future Amortization of Intangible Assets:
Weighted average remaining lease term	10 years
2017	$ 41,896
2018	30,763
2019	21,963
2020	15,904
2021	11,429
Thereafter	32,119
Finite-lived intangibles, net	154,074
Below Market Rents
Future Amortization of Intangible Liabilities:
2017	(15,591)
2018	(14,460)
2019	(12,754)
2020	(11,532)
2021	(9,634)
Thereafter	(23,999)
Finite-lived intangible liabilities, net	$ (87,970)
Weighted average remaining lease term (in years)	7 years
Above Market Ground Lease
Future Amortization of Intangible Liabilities:
2017	$ (46)
2018	(46)
2019	(46)
2020	(46)
2021	(46)
Thereafter	(1,581)
Finite-lived intangible liabilities, net	$ (1,811)
Weighted average remaining lease term (in years)	39 years
Below Market Ground Lease
Future Amortization of Intangible Assets:
2017	$ 487
2018	470
2019	454
2020	439
2021	425
Thereafter	16,069
Finite-lived intangible assets, net	$ 18,344	$ 0
Weighted average remaining lease term	67 years
Above Market Rents
Future Amortization of Intangible Assets:
2017	$ 9,169
2018	8,225
2019	6,316
2020	5,043
2021	3,805
Thereafter	7,702
Finite-lived intangible assets, net	$ 40,260	8,031
Weighted average remaining lease term	6 years
In Place Leases
Future Amortization of Intangible Assets:
2017	$ 47,877
2018	36,574
2019	27,993
2020	22,000
2021	16,879
Thereafter	33,928
Finite-lived intangible assets, net	$ 185,251	$ 112,937
Weighted average remaining lease term	6 years