Identified Intangible Assets and Liabilities

12 Months Ended

Dec. 31, 2019

Intangible Assets, Net (Excluding Goodwill) [Abstract]

Identified Intangible Assets and Liabilities

Identified Intangible Assets and Liabilities

The following summarizes our identified intangible assets (primarily above-market leases) and liabilities (primarily below-market leases) as of December 31, 2019 and 2018.

(Amounts in thousands)	As of December 31,
	2019			2018
Identified intangible assets:
Gross amount	$	129,552		$	308,895
Accumulated amortization	(98,587		)	(172,114		)
Total, net	$	30,965		$	136,781
Identified intangible liabilities (included in deferred revenue):
Gross amount	$	316,119		$	503,373
Accumulated amortization	(262,580		)	(341,779		)
Total, net	$	53,539		$	161,594

     Amortization of acquired below-market leases, net of acquired above-market leases, resulted in an increase to rental revenues of $19,830,000, $38,573,000 and $46,103,000 for the years ended December 31, 2019, 2018 and 2017, 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, 2020 is as follows:

(Amounts in thousands)
2020	$	16,643
2021	11,934
2022	8,792
2023	6,261
2024	2,518

9.     Identified Intangible Assets and Liabilities - continued

Amortization of all other identified intangible assets (a component of depreciation and amortization expense) was $8,666,000, $18,018,000 and $25,057,000 for the years ended December 31, 2019, 2018 and 2017, respectively. Estimated annual amortization of all other identified intangible assets including acquired in-place leases for each of the five succeeding years commencing January 1, 2020 is as follows:

(Amounts in thousands)
2020	$	6,235
2021	4,697
2022	2,985
2023	2,898
2024	2,286