Intangible Assets and Goodwill

12 Months Ended

Dec. 31, 2022

Goodwill and Intangible Assets Disclosure [Abstract]

Intangible Assets

Identifiable intangible assets consisted of the following (in millions):


	December 31, 2021						December 31, 2022
	Gross Carrying Amount (1)		Accumulated Amortization (1)		Net Carrying Value		Gross Carrying Amount (1)		Accumulated Amortization (1)		Net Carrying Value
Listing relationships	$	43	$	(16)	$	27	$	35	$	(13)	$	22
Trade names	33		(18)		15		33		(25)		8
Developed technology	23		(21)		2		—		—		—
Customer contacts	4		(4)		—		—		—		—
Other	10		(2)		8		9		(5)		4
Total intangible assets	$	113	$	(61)	$	52	$	77	$	(43)	$	34

(1)Excludes write off of intangible assets that have been fully amortized.

Amortization expense related to intangible assets for the years ended December 31, 2020, 2021, and 2022 was $36.2 million, $23.7 million, and $19.1 million, respectively.

Estimated future amortization expense for intangible assets as of December 31, 2022 was as follows (in millions):


Year Ending December 31,	Amount
2023	$	11
2024	6
2025	5
2026	4
2027	4
Thereafter	4
Total future amortization expense	$	34

Goodwill

The changes in the carrying amount of goodwill for the years ended December 31, 2021 and 2022 were as follows (in millions):


	Amount



Balance as of December 31, 2020	$	656

Foreign currency translation adjustments	(3)
Balance as of December 31, 2021	653

Foreign currency translation adjustments	(3)
Balance as of December 31, 2022	$	650