Goodwill and Other Intangibles (Projected Amortization Expense and Adjustments) (Details) $ in Thousands	Dec. 31, 2015 USD ($)
Acquired Finite-Lived Intangible Assets [Line Items]
Below-market lease liabilities, amortization income, 2016	$ 21,304
Below-market lease liabilities, amortization income, 2017	21,140
Below-market lease liabilities, amortization income, 2018	20,804
Below-market lease liabilities, amortization income, 2019	19,971
Below-market lease liabilities, amortization income, 2020	18,661
In-Place Leases [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization expense, 2016	172,641
Amortization expense, 2017	157,734
Amortization expense, 2018	144,024
Amortization expense, 2019	132,307
Amortization expense, 2020	122,660
Leasing Commissions [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization expense, 2016	720
Amortization expense, 2017	693
Amortization expense, 2018	506
Amortization expense, 2019	434
Amortization expense, 2020	22,557
Above-Market Lease Assets [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization expense, 2016	25,901
Amortization expense, 2017	25,559
Amortization expense, 2018	24,999
Amortization expense, 2019	23,037
Amortization expense, 2020	$ 413