Identified Intangible Assets and Liabilities

3 Months Ended

Mar. 31, 2017

Identified Intangible Assets and Liabilities [Abstract]

Identified Intangible Assets and Liabilities

8. Identified Intangible Assets and Liabilities

The following summarizes our identified intangible assets (primarily above-market leases) and liabilities (primarily acquired below-market leases) as of March 31,2017 and December 31,2016.

(Amounts in thousands)	Balance as of
	March 31, 2017		December 31, 2016
Identified intangible assets:
Gross amount	$	387,677	$	400,061
Accumulated amortization		(203,668)		(207,330)
Net	$	184,009	$	192,731
Identified intangible liabilities (included in deferred revenue):
Gross amount	$	586,969	$	586,969
Accumulated amortization		(335,798)		(323,183)
Net	$	251,171	$	263,786

Amortization of acquired below-market leases, net of acquired above-market leases, resulted in an increase to rental income of $11,459,000and $17,507,000 for the three months endedMarch 31,2017 and2016, respectively.Estimated annual amortization of acquired below-market leases, net of acquired above-market leases, for each of the five succeeding years commencing January 1, 2018 is as follows:

(Amounts in thousands)
2018	$	44,346
2019		32,168
2020		23,343
2021		18,159
2022		15,009

Amortization of all other identified intangible assets (a component of depreciation and amortization expense) was $7,108,000 and $7,793,000 for the three months endedMarch 31,2017 and 2016, respectively. Estimated annual amortization of all other identified intangible assets including acquired in-place leases, customer relationships, and third party contracts for each of the five succeeding years commencing January 1, 2018 is as follows:

(Amounts in thousands)
2018	$	20,059
2019		15,720
2020		12,275
2021		11,177
2022		9,395

We are a tenant under ground leases for certain properties. Amortization of these acquired below-market leases, net of above-market leases, resulted in an increase to rent expense (a component of operating expense) of $458,000 and $458,000 for the three months endedMarch 31,2017 and 2016. Estimated annual amortization of these below-market leases, net of above-market leases, for each of the five succeeding years commencing January 1, 2018 is as follows:

(Amounts in thousands)
2018	$	1,832
2019		1,832
2020		1,832
2021		1,832
2022		1,832