4. Acquired Intangible Assets and Liabilities

During the year ended December 31, 2016, through the acquisition of the Reston Campus Expansion, we added $7.5 million of new intangible assets and $0.4 million of new intangible liabilities with a weighted average life of 4.3 years and 5.7 years, respectively. We did not add new intangible assets or liabilities during the year ended December 31, 2015.

Above-market and below-market lease intangibles and other intangibles balances at December 31, 2016, and 2015, are as follows (in thousands):


	December 31,		December 31,
	2016		2015
Lease contracts above-market value	$	2,080	$	2,191
Accumulated amortization		(1,698)		(1,756)
Lease contracts above-market value, net	$	382	$	435

Lease contracts below-market value	$	9,731	$	9,972
Accumulated amortization		(5,439)		(5,279)
Lease contracts below-market value, net	$	4,292	$	4,693

Other identified intangible assets	$	20,218	$	13,960
Accumulated amortization		(10,687)		(9,681)
Other identified intangible assets, net	$	9,531	$	4,279

The net effect of amortization of acquired above‑market and below‑market leases resulted in an increase to rental revenue of $0.5 million, $0.5 million, and $0.6 million, for the years ended December 31, 2016, 2015, and 2014, respectively. The estimated amortization of acquired below‑market leases, net of acquired above‑market leases for each of the five succeeding fiscal years, which will be a net increase to rental revenue, is as follows (in thousands):


Year Ending December 31,
2017	$	600
2018		603
2019		280
2020		175
2021		168
Thereafter		2,084
Total	$	3,910

Amortization of all other identified intangible assets was $2.0 million, $2.0 million, and $3.4 million, for the years ended December 31, 2016, 2015, and 2014, respectively. The estimated amortization of all other identified intangible assets for each of the five succeeding fiscal years is as follows (in thousands):


Year Ending December 31,
2017	$	3,410
2018		2,028
2019		1,509
2020		851
2021		807
Thereafter		926
Total	$	9,531