OTHER INTANGIBLE ASSETS

A schedule of our intangible assets and liabilities and related accumulated amortization and accretion as of September 30, 2018 and December 31, 2017 is as follows:



	Assets								Liabilities
September 30, 2018	Acquired Above-Market Leases			Acquired In-Place Leases			Trade Name and License		Acquired Below-Market Leases
	(in thousands)
Gross balance	$	146		$	17,988		$	2,957	$	(6,618	)
Accumulated amortization	(40		)	(10,367		)	—		3,267
	$	106		$	7,621		$	2,957	$	(3,351	)
Average useful life (in years)	3			7			Indefinite		4



	Assets							Liabilities
December 31, 2017	Acquired Above-Market Leases		Acquired In-Place Leases			Trade Name and License		Acquired Below-Market Leases
	(in thousands)
Gross balance	$	37	$	11,087		$	2,957	$	(2,902	)
Accumulated amortization	—		(7,700		)	—		1,832
	$	37	$	3,387		$	2,957	$	(1,070	)
Average useful life (in years)	7		9			Indefinite		5

The amortization of the acquired above-market leases, which decreased rental and other property income, was $14,000 and $0 for the three months ended September 30, 2018 and 2017, respectively, and $40,000 and $3,000 for the nine months ended September 30, 2018 and 2017, respectively. The amortization of the acquired in-place leases included in depreciation and amortization expense was $927,000 and $212,000 for the three months ended September 30, 2018 and 2017, respectively, and $2,769,000 and $623,000 for the nine months ended September 30, 2018 and 2017, respectively. Tax abatement amortization included in rental and other property operating expenses was $0 and $0 for the three months ended September 30, 2018 and 2017, respectively, and $0 and $276,000 for the nine months ended September 30, 2018 and 2017, respectively. The amortization of the acquired below-market ground lease included in rental and other property operating expenses was $0 and $23,000 for the three months ended September 30, 2018 and 2017, respectively, and $0 and $93,000 for the nine months ended September 30, 2018 and 2017, respectively. The amortization of the acquired below-market leases included in rental and other property income was $478,000 and $231,000 for the three months ended September 30, 2018 and 2017, respectively, and $1,711,000 and $869,000 for the nine months ended September 30, 2018 and 2017, respectively.

A schedule of future amortization and accretion of acquisition related intangible assets and liabilities as of September 30, 2018, is as follows:



	Assets				Liabilities
Years Ending December 31,	Acquired Above-Market Leases		Acquired In-Place Leases		Acquired Below-Market Leases
	(in thousands)
2018 (Three months ending December 31, 2018)	$	11	$	922	$	(479	)
2019	54		3,222		(1,540		)
2020	18		1,535		(751		)
2021	5		798		(347		)
2022	5		562		(234		)
Thereafter	13		582		—
	$	106	$	7,621	$	(3,351	)