Supplemental Detail for Certain Components of Consolidated Balance Sheets - Acquired Lease Intangible Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Acquired lease intangible assets, net
Acquired in-place leases	$ 1,301,834	$ 1,272,897
Accumulated amortization of acquired in-place leases	(495,883)	(444,221)
Acquired above-market leases	562,801	487,933
Accumulated amortization of acquired above-market leases	(140,172)	(121,679)
Total acquired lease intangible assets, net	$ 1,228,580	$ 1,194,930