The Company assesses goodwill for impairment at the reporting unit level at least annually, as of January 31, or on an interim basis if an event occurs or circumstances change that would, more likely than not, reduce the fair value of the reporting unit below its carrying value.

Reporting units are determined based on the components of a Company's operating segments that constitute a business for which financial information is available and for which operating results are regularly reviewed by segment management. Through the first half of fiscal year 2020, the Company had two reporting units: (1) Service Assurance and (2) Security. As part of its continued integration efforts, effective during the third quarter of fiscal year 2020, the Company reorganized its business units. As a result of this change, the Company reduced the number of reporting units from two reporting units to one reporting unit. The former Service Assurance and Security reporting units were combined as result of organizational changes made to fully integrate the resources and assets of the Service Assurance and Security business units.

In fiscal years 2020 and 2019, the Company's quantitative impairment tests indicated that goodwill was not impaired. The Company considered the current and expected future economic and market conditions surrounding the COVID-19 pandemic to be a triggering event. As such, the Company performed a quantitative analysis as of March 31, 2020. The quantitative impairment test indicated goodwill was not impaired as of March 31, 2020.

The Company determined the fair value of its reporting unit by preparing a discounted cash flow analysis using forward looking projections of the reporting unit's future operating results and by comparing the value of the reporting unit to the implied market value of selected peers. The assumptions used in the discounted cash flow analysis include: projected revenues, selling margins, and other operating expenditures. The discount rate used is a cost of equity method, which is essentially equal to the "market participant" weighted-average cost of capital (WACC). The goodwill fair value substantially exceeded the carrying value.

The change in the carrying amount of goodwill for the fiscal year ended March 31, 2020 is due to the acquisitions of Eastwind and Gigavation and impact of foreign currency translation adjustments related to asset balances that are recorded in currencies other than the U.S. Dollar.





















Balance at March 31, 2018	$	1,712,764
Divestiture of the HNT tools business	(4,414)
Foreign currency translation impact	7,135
Balance at March 31, 2019	$	1,715,485
Goodwill attributed to the Eastwind acquisition	1,003
Goodwill attributed to the Gigavation acquisition	3,816
Foreign currency translation impact	5,376
Balance at March 31, 2020	$	1,725,680

The net carrying amounts of intangible assets were $582.2 million and $669.1 million at March 31, 2020 and 2019, respectively. Intangible assets acquired in a business combination are recorded under the acquisition method of accounting at their estimated fair values at the date of acquisition. The Company amortizes intangible assets over their estimated useful lives, except for the acquired trade name which resulted from the Network General acquisition, which has an indefinite life and thus is not amortized. The carrying value of the indefinite lived trade name is evaluated for potential impairment annually or more frequently if events or changes in circumstances indicate that the asset might be impaired.

During fiscal year 2019, the Company performed a quantitative analysis on certain intangible assets related to the HNT tools business, which has since been divested. The fair value for the intangible assets related to the HNT tools business was calculated considering a range of potential transaction prices which the Company considers to be a Level 3 measurement. The fair value of these intangible assets was determined to be less than the carrying value, and as a result, the Company recognized an impairment charge of $35.9 million in the twelve months ended March 31, 2019. The impairment charge was recorded within a separate operating expense line item in the Company's consolidated statements of operations during the twelve months ended March 31, 2019.

During fiscal year 2019, the Company completed the divestiture of the HNT tools business. As a result, the net carrying value of the Company's intangible assets was reduced by $10.2 million.

In fiscal year 2020 and 2019, the Company's annual impairment tests indicated that the acquired trade name was not impaired. In the fourth quarter of fiscal year 2019, the Company completed its annual impairment test of the indefinite lived intangible at January 31, 2020 using the qualitative Step 0 assessment. No impairment indicators were observed at January 31, 2020. The Company considered the current and expected future economic and market conditions surrounding the COVID-19 pandemic and concluded that it was not more likely than not that the trade name was impaired and therefore a quantitative Step 1 assessment was not performed as of March 31, 2020.

Intangible assets include the indefinite lived trade name with a carrying value of $18.6 million and the following amortizable intangible assets at March 31, 2020 (in thousands):


	Cost		Accumulated Amortization		Net
Developed technology	$	249,675	$	(191,876)	$	57,799
Customer relationships	767,366		(275,361)		492,005
Distributor relationships and technology licenses	6,785		(6,321)		464
Definite-lived trademark and trade name	39,059		(26,246)		12,813
Core technology	7,192		(7,074)		118
Net beneficial leases	336		(336)		—
Non-compete agreements	292		(292)		—
Leasehold interest	500		(500)		—
Backlog	16,223		(16,223)		—
Capitalized software	3,317		(3,202)		115
Other	1,208		(943)		265
	$	1,091,953	$	(528,374)	$	563,579

Intangible assets include the indefinite lived trade name with a carrying value of $18.6 million and the following amortizable intangible assets at March 31, 2019 (in thousands):


	Cost		Accumulated Amortization		Net
Developed technology	$	242,259	$	(168,289)	$	73,970
Customer relationships	772,969		(218,043)		554,926
Distributor relationships and technology licenses	6,882		(5,237)		1,645
Definite-lived trademark and trade name	39,304		(20,586)		18,718
Core technology	7,192		(6,845)		347
Net beneficial leases	336		(336)		—
Non-compete agreements	292		(292)		—
Leasehold interest	500		(500)		—
Backlog	16,397		(16,397)		—
Capitalized software	3,317		(2,690)		627
Other	1,208		(923)		285
	$	1,090,656	$	(440,138)	$	650,518

Amortization included as product revenue consists of amortization of backlog. Amortization included as cost of product revenue consists of amortization of developed technology, distributor relationships and technology licenses, core technology and software. Amortization included as operating expense consists of all other intangible assets. The following table provides a summary of amortization expense during the fiscal years ended March 31, 2020, 2019, and 2018 (in thousands).


	Years Ended March 31,
	2020		2019		2018
Amortization of intangible assets included as:
Product revenue	$	—	$	—	$	9
Cost of product revenue	26,664		34,039		40,286
Operating expense	64,525		74,325		76,661
	$	91,189	$	108,364	$	116,956

The weighted average amortization period of developed technology and core technology is 11.2 years. The weighted average amortization period for customer and distributor relationships is 15.9 years. The weighted average amortization period for trademarks and trade names is 8.6 years. The weighted average amortization period for capitalized software is 3.0 years. The weighted average amortization period for all amortizing intangible assets is 14.6 years.