Supplemental Detail for Certain Components of Consolidated Balance Sheets (Details) (USD $)
In Thousands, unless otherwise specified
Mar. 31, 2015
Dec. 31, 2014
Acquired lease intangible assets, net    
Acquired in-place leases $ 1,021,247 $ 1,005,244
Accumulated amortization of acquired in-place leases (198,976) (177,722)
Acquired above-market leases 279,650 252,581
Accumulated amortization of acquired above-market leases (45,076) (40,379)
Acquired lease intangible assets $ 1,056,845 $ 1,039,724