Acquired Intangible Assets and Liabilities

The following summarizes our acquired intangible assets (real estate intangibles, comprised of acquired in-place lease value and tenant relationship value along with acquired above-market lease value) and intangible liabilities (acquired below-market lease value) as of March 31, 2019 and December 31, 2018.



	Balance as of
(Amounts in thousands)	March 31, 2019			December 31, 2018
Real Estate Intangibles:
Acquired in-place lease value:
Gross amount (1)	$	1,450,914		$	1,569,401
Accumulated amortization	(840,778		)	(795,033		)
Net	$	610,136		$	774,368
Tenant relationship value:
Gross amount (1)	$	1,966,006		$	2,339,606
Accumulated amortization	(322,791		)	(291,818		)
Net	$	1,643,215		$	2,047,788
Acquired above-market leases:
Gross amount	$	278,592		$	277,796
Accumulated amortization	(172,548		)	(158,037		)
Net	$	106,044		$	119,759
Acquired below-market leases:
Gross amount	$	442,936		$	442,535
Accumulated amortization	(250,269		)	(242,422		)
Net	$	192,667		$	200,113


(1)	In connection with the deconsolidation of Ascenty, $120.0 million of acquired in-place lease value and $375.0 million of tenant relationship value were written off during the three months ended March 31, 2019.

Amortization of acquired below-market leases, net of acquired above-market leases, resulted in a decrease in rental revenues of $6.2 million and $6.9 million for the three months ended March 31, 2019 and 2018, respectively. The expected average remaining lives for acquired below-market leases and acquired above-market leases is 8.0 years and 2.7 years, respectively, as of March 31, 2019. Estimated annual amortization of acquired below-market leases, net of acquired above-market leases, for each of the five succeeding years and thereafter, commencing April 1, 2019 is as follows:



(Amounts in thousands)
Remainder of 2019	$	(9,150	)
2020	(3,912		)
2021	889
2022	7,923
2023	12,070
Thereafter	78,803
Total	$	86,623

Amortization of acquired in-place lease value (a component of depreciation and amortization expense) was $44.9 million and $57.0 million for the three months ended March 31, 2019 and 2018, respectively. The expected average amortization period for acquired in-place lease value is 5.9 years as of March 31, 2019. The weighted average remaining contractual life for acquired leases excluding renewals or extensions is 5.5 years as of March 31, 2019. Estimated annual amortization of acquired in-place lease value for each of the five succeeding years and thereafter, commencing April 1, 2019 is as follows:



(Amounts in thousands)
Remainder of 2019	$	101,543
2020	111,585
2021	87,036
2022	65,153
2023	53,596
Thereafter	191,223
Total	$	610,136

Amortization of tenant relationship value (a component of depreciation and amortization expense) was approximately $38.0 million and $31.0 million for the three months ended March 31, 2019 and 2018, respectively. As of March 31, 2019, the weighted average remaining contractual life for tenant relationship value was 14.0 years. Estimated annual amortization of tenant relationship value for each of the five succeeding years and thereafter, commencing April 1, 2019 is as follows:



(Amounts in thousands)
Remainder of 2019	$	92,301
2020	123,069
2021	123,069
2022	123,069
2023	123,069
Thereafter	1,058,638
Total	$	1,643,215