Goodwill related to our June 15, 2015 acquisition of Hudson Global Resources Management’s U.S. IT staffing business (“Hudson IT”) totaled $8.4 million. Goodwill related to our July 13, 2017 acquisition of the services division of InfoTrellis totaled $27.4 million. During 2018, the Company recorded a goodwill impairment related to the InfoTrellis acquisition of $9.7 million. Goodwill related to our October 1, 2020 acquisition of AmberLeaf totaled $6.4 million.

The Company is amortizing the identifiable intangible assets on a straight-line basis over estimated average lives ranging from 3 to 12 years. Identifiable intangible assets were comprised of the following as of September 30, 2022 and December 31, 2021:


	As of September 30, 2022
(Amounts in thousands)	Amortization Period (In Years)		Gross Carrying Value		Accumulative Amortization		Net Carrying Value
IT Staffing Services:
Client relationships		12	$	7,999	$	4,861	$	3,138
Covenant-not-to-compete		5		319		319		—
Trade name		3		249		249		—
Data and Analytics Services:
Client relationships		12		19,641		7,731		11,910
Covenant-not-to-compete		5		1,201		967		234
Trade name		5		1,711		1,467		244
Technology		7		1,979		1,120		859

Total Intangible Assets			$	33,099	$	16,714	$	16,385


	As of December 31, 2021
(Amounts in thousands)	Amortization Period (In Years)		Gross Carrying Value		Accumulative Amortization		Net Carrying Value
IT Staffing Services:
Client relationships		12	$	7,999	$	4,361	$	3,638
Covenant-not-to-compete		5		319		319		—
Trade name		3		249		249		—
Data and Analytics Services:
Client relationships		12		19,641		6,503		13,138
Covenant-not-to-compete		5		1,201		788		413
Trade name		5		1,711		1,211		500
Technology		7		1,979		908		1,071

Total Intangible Assets			$	33,099	$	14,339	$	18,760

Amortization expense for the three and nine month periods ended September 30, 2022 totaled $791,000 and $2.4 million, respectively and is included in selling, general and administrative expenses in the Consolidated Statement of Operations. For the three and nine month periods ended September 30, 2021, amortization expense was $792,000 and $2.4 million, respectively.

The estimated aggregate amortization expense for intangible assets for the years ending December 31, 2022 through 2026 is as follows:


	Years Ended December 31,
	2022		2023		2024		2025		2026

	(Amounts in thousands)
Amortization expense	$	2,987	$	2,772	$	2,693	$	2,553	$	2,413