Goodwill and Other Intangible Assets

12 Months Ended

Dec. 31, 2020

Goodwill and Intangible Assets Disclosure [Abstract]

Goodwill and Intangible Assets Disclosure [Text Block]

Goodwill and Other Intangible Assets

The changes in the carrying amounts of goodwill by segment were as follows:

(In thousands)	Domestic		International		Total
Balance at the end of 2018	$	782,664	$	64,880	$	847,544
Goodwill recorded in connection with the AbleVets acquisition	37,071		—		37,071
Foreign currency translation adjustment and other	—		(1,457)		(1,457)
Balance at the end of 2019	819,735		63,423		883,158
Purchase price allocation adjustments for the AbleVets acquisition	744		—		744
Goodwill recorded in connection with 2020 business acquisitions	33,709		—		33,709
Goodwill reduction in connection with divestiture transactions	—		(7,692)		(7,692)
Foreign currency translation adjustment and other	—		4,601		4,601
Balance at the end of 2020	$	854,188	$	60,332	$	914,520

A summary of net intangible assets is as follows:

	2020				2019
(In thousands)	Gross Carrying Amount		Accumulated Amortization		Gross Carrying Amount		Accumulated Amortization
Customer lists	$	494,615	$	312,044	$	500,914	$	271,211
Purchased software	354,228		337,811		364,144		353,722
Internal use software	207,696		123,280		174,572		99,272
Trade names	42,951		28,961		41,731		26,574
Other	50,535		18,680		49,389		15,532
Total	$	1,150,025	$	820,776	$	1,130,750	$	766,311
Intangible assets, net			$	329,249			$	364,439

Amortization expense for 2020, 2019 and 2018 was $85 million, $114 million and $109 million, respectively.

Estimated aggregate amortization expense for each of the next five years is as follows:

(In thousands)
2021	$	77,634
2022	72,328
2023	62,773
2024	55,886
2025	14,836