Real Estate Intangibles

3 Months Ended

Mar. 31, 2020

Goodwill and Intangible Assets Disclosure [Abstract]

The following is a summary of our real estate intangibles, excluding those classified as held for sale, as of the dates indicated (dollars in thousands):



	March 31, 2020			December 31, 2019
Assets:
In place lease intangibles	$	1,523,390		$	1,513,836
Above market tenant leases	60,484			59,540
Lease commissions	45,788			43,675
Gross historical cost	1,629,662			1,617,051
Accumulated amortization	(1,195,330		)	(1,181,158		)
Net book value	$	434,332		$	435,893

Weighted-average amortization period in years	10.4			10.3

Liabilities:
Below market tenant leases	$	86,233		$	99,035
Accumulated amortization	(40,354		)	(49,390		)
Net book value	$	45,879		$	49,645

Weighted-average amortization period in years	8.6			8.6

The following is a summary of real estate intangible amortization income (expense) for the periods presented (in thousands):



	Three Months Ended March 31,
	2020			2019
Rental income related to (above)/below market tenant leases, net	$	524		$	(155	)
Amortization related to in place lease intangibles and lease commissions	(35,976		)	(24,905		)

The future estimated aggregate amortization of intangible assets and liabilities is as follows for the periods presented (in thousands):



	Assets		Liabilities
2020	$	89,792	$	6,817
2021	68,777		8,313
2022	44,647		7,607
2023	37,400		5,343
2024	29,529		3,215
Thereafter	164,187		14,584
Total	$	434,332	$	45,879