The Company has recorded goodwill as a result of its various business combinations. Goodwill is recorded as the difference, if any, between the aggregate consideration paid for an acquisition and the fair value of the tangible assets and intangible assets acquired net of liabilities assumed, including noncontrolling interests. Changes in the Company’s goodwill balances recognized during the years ended December 31, 2021 and 2020 were as follows (in thousands):

	1/1/2021		Foreign currency translation			12/31/2021
U.S. Secure Services	$	316,366	$	—		$	316,366
Electronic Monitoring and Supervision Services		289,570		—			289,570
Reentry Services		148,873		—			148,873
International Services		441		(25	)		416
Total Goodwill	$	755,250	$	(25	)	$	755,225

	1/1/2020		Impairment charges [1]			Foreign currency translation		12/31/2020
U.S. Secure Services	$	316,366	$	—		$	—	$	316,366
Electronic Monitoring and Supervision Services		289,570		—			—		289,570
Reentry Services		170,019		(21,146	)		—		148,873
International Services		401		-			40		441
Total Goodwill	$	776,356	$	(21,146	)	$	40	$	755,250

[1] The Company recorded an impairment charge in its Reentry Services reporting unit for the year ended December 31, 2020.

Intangible assets consisted of the following as of December 31, 2021 and 2020 (in thousands):

	Weighted		December 31, 2021							December 31, 2020
	Average Useful Life (years)		Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount		Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount
Facility management contracts		16.3	$	308,369	$	(189,163	)	$	119,206	$	308,398	$	(168,848	)	$	139,550
Technology		7.3		33,700		(31,982	)		1,718		33,700		(30,703	)		2,997
Trade names	Indefinite			45,200		—			45,200		45,200		—			45,200
Total acquired intangible assets			$	387,269	$	(221,145	)	$	166,124	$	387,298	$	(199,551	)	$	187,747

The accounting for recognized intangible assets is based on the useful lives to the reporting entity. Intangible assets with finite useful lives are amortized over their useful lives and intangible assets with indefinite useful lives are not amortized. The Company estimates the useful lives of its intangible assets taking into consideration (i) the expected use of the asset by the Company, (ii) the expected useful lives of other related assets or groups of assets, (iii) legal or contractual limitations, (iv) the Company's historical experience in renewing or extending similar

arrangements, (v) the effects of obsolescence, demand, competition and other economic factors and (vi) the level of maintenance expenditures required to obtain the expected cash flows from the asset.

Amortization expense was $21.6 million, $22.3 million and $22.3 million for the years ended December 31, 2021, 2020 and 2019, respectively, and primarily related to the U.S. Secure Services and Reentry Services segments’ amortization of intangible assets for acquired management contracts. The Company relies on its historical experience in determining the useful life of facility management contracts. The Company makes assumptions related to acquired facility management contracts based on the competitive environment for individual contracts, our historical success rates in retaining contracts, the supply of available beds in the market, changes in legislation, the projected profitability of the facilities and other market conditions. As of December 31, 2021, the weighted average period before the next contract renewal or extension for the facility management contracts was approximately 2.0 years. Although the facility management contracts acquired have renewal and extension terms in the near term, the Company has historically maintained these relationships beyond the contractual periods.

Estimated amortization expense related to the Company’s finite-lived intangible assets for 2022 through 2026 and thereafter is as follows (in thousands):

Fiscal Year	Total Amortization Expense
2022	$	16,307
2023		13,484
2024		9,751
2025		9,263
2026		7,170
Thereafter		64,949
	$	120,924