Intangible Assets

Intangible assets with finite lives are as follows:



	As of April 30, 2020
	Weighted Average Amortization Period	Gross Carrying Amount		Accumulated Amortization	Net Carrying Amount
Customer relationships	20.4	$	284,558,000	76,205,000	$	208,353,000
Technologies	13.7	97,649,000		63,866,000	33,783,000
Trademarks and other	16.6	32,526,000		14,500,000	18,026,000
Total		$	414,733,000	154,571,000	$	260,162,000



	As of July 31, 2019
	Weighted Average Amortization Period	Gross Carrying Amount		Accumulated Amortization	Net Carrying Amount
Customer relationships	20.5	$	276,834,000	66,484,000	$	210,350,000
Technologies	12.7	92,649,000		59,522,000	33,127,000
Trademarks and other	16.7	31,026,000		12,613,000	18,413,000
Total		$	400,509,000	138,619,000	$	261,890,000

The weighted average amortization period in the above table excludes fully amortized intangible assets.

Amortization expense for the three months ended April 30, 2020 and 2019 was $5,517,000 and $4,536,000, respectively. Amortization expense for the nine months ended April 30, 2020 and 2019 was $15,952,000 and $13,113,000, respectively.

The estimated amortization expense consists of the following for the fiscal years ending July 31:



2020	$	21,445,000
2021	21,040,000
2022	19,458,000
2023	19,458,000
2024	18,766,000

We review net intangible assets with finite lives for impairment when an event occurs indicating the potential for impairment. In light of the COVID-19 pandemic, during the three months ended April 30, 2020, we evaluated whether our long-lived assets, including intangibles with finite lives, were impaired. Based on our assessment, we believe that the carrying values of our net intangible assets were recoverable as of April 30, 2020. However, if current poor business conditions further deteriorate, we may be required to record impairment losses in the future, which could increase the amortization of intangibles in our fourth quarter of fiscal 2020. Any impairment charges that we may record in the future could be material to our results of operations and financial condition.