Fair Value Measurements - Schedule of Assets at Fair Value on Nonrecurring Basis (Details) - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended 12 Months Ended
Jun. 30, 2015
Jun. 30, 2014
Jun. 30, 2015
Jun. 30, 2014
Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Total Impairment Charges $ (33,766) $ (27,627) $ (35,424) $ (29,334)  
Fair Value, Measurements, Nonrecurring          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Long-lived assets held and used 32,671   32,671    
Long-lived assets held and used, Dispositions (3,207)   (3,207)   $ 0
Lease intangible assets, Dispositions 0   0   0
Long-lived assets held for sale, Dispositions (1,096)   (1,096)   (26,721)
Long-lived assets held and used, Impairment Charges     (26,110)   (20,679)
Lease intangible assets, Impairment Charges     (1,493)   4,317
Long-lived assets held for sale, Impairment Charges     (7,821)   (20,074)
Total Impairment Charges     (35,424)   (36,436)
Fair Value, Measurements, Nonrecurring | Level 1          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Long-lived assets held and used 0   0   0
Long-lived assets held and used 0   0   0
Lease intangible assets 0   0   0
Fair Value, Measurements, Nonrecurring | Level 2          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Long-lived assets held and used 0   0   0
Long-lived assets held and used 0   0   0
Lease intangible assets 0   0   0
Fair Value, Measurements, Nonrecurring | Level 3          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Long-lived assets held and used 35,878   35,878   37,278
Long-lived assets held and used 2,303   2,303   10,013
Lease intangible assets 43,143   43,143   92,679
Fair Value | Fair Value, Measurements, Nonrecurring          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Long-lived assets held and used         37,278
Long-lived assets held and used 2,303   2,303   10,013
Lease intangible assets $ 42,047   $ 42,047   $ 65,958