Identified Intangible Assets and Liabilities

Identified intangible assets and liabilities associated with our property acquisitions are as follows (in thousands):



	December 31,
	2015			2014
Identified Intangible Assets:
Above-market leases (included in Other Assets, net)	$	37,595		$	38,121
Above-market leases - Accumulated Amortization	(14,421		)	(11,331		)
Below-market assumed mortgages (included in Debt, net)	1,671			4,713
Below-market assumed mortgages - Accumulated Amortization	(1,307		)	(2,352		)
Valuation of in place leases (included in Unamortized Lease Costs, net)	148,904			132,554
Valuation of in place leases - Accumulated Amortization	(67,762		)	(56,571		)
	$	104,680		$	105,134
Identified Intangible Liabilities:
Below-market leases (included in Other Liabilities, net)	$	50,370		$	42,830
Below-market leases - Accumulated Amortization	(22,080		)	(19,612		)
Above-market assumed mortgages (included in Debt, net)	32,777			34,113
Above-market assumed mortgages - Accumulated Amortization	(27,272		)	(27,411		)
	$	33,795		$	29,920

These identified intangible assets and liabilities are amortized over the applicable lease terms or the remaining lives of the assumed mortgages, as applicable.

The net amortization of above-market and below-market leases (decreased) increased rental revenues by $(.5) million, $(1.7) million and $.6 million in 2015, 2014 and 2013, respectively. The significant year over year change in rental revenues from 2014 to 2013 is primarily due to the acquisition of a partner’s 50% interest in an unconsolidated joint venture in December 2013. The estimated net amortization of these intangible assets and liabilities will decrease rental revenues for each of the next five years as follows (in thousands):



2016	$	615
2017	930
2018	853
2019	394
2020	284

The amortization of the in place lease intangible assets recorded in depreciation and amortization, was $12.3 million, $12.0 million and $11.6 million in 2015, 2014 and 2013, respectively. The estimated amortization of this intangible asset will increase depreciation and amortization for each of the next five years as follows (in thousands):



2016	$	10,757
2017	10,210
2018	9,498
2019	8,175
2020	7,462

The net amortization of above-market and below-market assumed mortgages decreased net interest expense by $.7 million, $1.0 million and $10.4 million in 2015, 2014 and 2013, respectively. The significant year over year change in expense from 2013 to 2014 is primarily due to a $9.7 million write-off in 2013 of an above-market assumed mortgage intangible due to the early payoff of the related mortgage. The estimated net amortization of these intangible assets and liabilities will decrease net interest expense for each of the next five years as follows (in thousands):



2016	$	819
2017	940
2018	1,047
2019	1,047
2020	276