Goodwill represents the excess of the purchase price over the fair value of net assets of acquired businesses and is not amortized. Goodwill and other intangible assets are tested for impairment at a reporting unit level. The annual impairment test of goodwill and intangible assets is performed as of December 1 of each fiscal year.

The Company uses qualitative factors to determine whether it is more likely than not (likelihood of more than 50%) that the fair value of a reporting unit exceeds its carrying amount, including goodwill. Some of the qualitative factors used in applying this test include consideration of macroeconomic conditions, industry and market conditions, cost factors affecting the business, overall financial performance of the business, and performance of the share price of the Company.

If qualitative factors are not deemed sufficient to conclude that the fair value of the reporting unit more likely than not exceeds its carrying value, then a one-step approach is applied in making an evaluation. The evaluation utilizes multiple valuation methodologies, including a market approach (market price multiples of comparable companies) and an income approach (discounted cash flow analysis). The computations require management to make significant estimates and assumptions, including, among other things, selection of comparable publicly traded companies, the discount rate applied to future earnings reflecting a weighted average cost of capital, and earnings growth assumptions. A discounted cash flow analysis requires management to make various assumptions about future sales, operating margins, capital expenditures, working capital, and growth rates. If the evaluation results in the fair value of the goodwill for the reporting unit being lower than the carrying value, an impairment charge is recorded.

Definite-lived intangible assets are amortized over their estimated useful lives and tested for impairment if events or changes in circumstances indicate that the asset may be impaired.

The carrying amount and accumulated amortization of the Company’s intangible assets at each balance sheet date are as follows (in thousands):

	Weighted
	Average
	Remaining		Gross
	Life		Carrying		Accumulated
As of May 31, 2021	(in years)		Amount		Amortization		Net
Amortized intangible assets
Trademarks and trade names		11.7	$	27,561	$	8,740	$	18,821
Customer lists		6.6		75,877		44,226		31,651
Non-compete		3.3		877		713		164
Patent		—		783		783		—
Total		8.5	$	105,098	$	54,462	$	50,636

As of February 28, 2021
Amortized intangible assets
Trademarks and trade names		11.9	$	27,561	$	8,194	$	19,367
Customer lists		6.8		75,862		42,727		33,135
Non-compete		3.1		877		667		210
Patent		—		783		783		—
Total		8.7	$	105,083	$	52,371	$	52,712

Aggregate amortization expense for the three months ended May 31, 2021 and May 31, 2020 was $2.1 million and $2.0 million, respectively.

The Company’s estimated amortization expense for the current and next four fiscal years is as follows (in thousands):

Changes in the net carrying amount of goodwill as of the dates indicated are as follows (in thousands):

During fiscal year 2021, $6.1 million was added to goodwill related to the acquisition of Infoseal.