Acquired Lease Intangibles Schedule of Future Amortization Expense and Minimum Rent (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017 USD ($)
Amortization Expense [Abstract]
2016	$ 72,769
Future Accretion, Year Two	28,754
2017	54,743
Future Accretion, Year Three	27,710
2018	41,211
Future Accretion, Year Four	27,106
2019	32,893
Future Accretion, Year Five	25,440
2020	25,202
Net Accretion [Abstract]
2016	29,654
Above/Below Market Ground Lease [Member]
Amortization Expense [Abstract]
2016	1,560
2017	1,550
2018	1,544
2019	1,545
2020	$ 1,555