Identified Intangible Assets and Liabilities (Tables)

3 Months Ended

Mar. 31, 2016

Finite-Lived Intangible Assets [Line Items]

Schedule of Identified Intangible Assets and Intangible Liabilities [Table Text Block]

(Amounts in thousands)	Balance as of
	March 31, 2016		December 31, 2015
Identified intangible assets:
Gross amount	$	406,482	$	415,261
Accumulated amortization		(188,094)		(187,360)
Net	$	218,388	$	227,901
Identified intangible liabilities (included in deferred revenue):
Gross amount	$	607,241	$	643,488
Accumulated amortization		(307,858)		(325,340)
Net	$	299,383	$	318,148

Below Market Leases Net Of Above Market Leases [Member]

Finite-Lived Intangible Assets [Line Items]

Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block]

(Amounts in thousands)
2017	$	44,463
2018		42,991
2019		30,973
2020		23,320
2021		18,263

Other Identified Intangible Assets [Member]

Finite-Lived Intangible Assets [Line Items]

Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block]

(Amounts in thousands)
2017	$	24,427
2018		20,063
2019		15,779
2020		12,345
2021		10,957

Tenant Under Ground Leases [Member]

Finite-Lived Intangible Assets [Line Items]

Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block]

(Amounts in thousands)
2017	$	1,832
2018		1,832
2019		1,832
2020		1,832
2021		1,832