The goodwill balances as of December 31, 2023 and June 30, 2024, and the changes in the six months ended June 30, 2024 were as follows:


(in thousands)	Travel Marketplace		SaaS Platform		Total
Balance as of December 31, 2023	$	80,635	$	7,421	$	88,056


Foreign Currency Translation Adjustments and Other	(5,298)		—		(5,298)

Balance as of June 30, 2024	$	75,337	$	7,421	$	82,758

Our indefinite-lived intangible assets relate to trade names acquired in various acquisitions in past periods. Intangible assets, net includes indefinite-life intangible assets of $10.7 million as of June 30, 2024 and $10.7 million as of December 31, 2023, respectively.

Definite-life intangible assets, net consisted of the following as of June 30, 2024:


(in thousands)	Gross Carrying Amount		Accumulated Amortization		Net Carrying Amount
Customer relationships	$	89,341	$	(39,832)	$	49,509
Trade name	19,847		(6,909)		12,938
Supplier relationships	6,526		(1,739)		4,787
Developed technology	18,402		(4,399)		14,003
Assembled workforce	501		(103)		398
	$	134,617	$	(52,982)	$	81,635

Definite-life intangible assets, net consisted of the following as of December 31, 2023:


(in thousands)	Gross Carrying Amount		Accumulated Amortization		Net Carrying Amount
Customer relationships	$	93,139	$	(36,454)	$	56,685
Trade name	21,265		(6,408)		14,857
Supplier relationships	5,767		(1,538)		4,229
Developed technology	18,402		(3,276)		15,126
Assembled workforce	501		(22)		479
	$	139,074	$	(47,698)	$	91,376

Amortization expense for intangible assets was $2.7 million and $2.3 million for the three months ended June 30, 2024 and 2023, respectively and $5.9 million and $4.3 million for the six months ended June 30, 2024 and 2023, respectively.

The estimated future amortization expense related to intangible assets with definite lives is as follows:


(in thousands)
Fiscal years ending December 31,
2024 (remaining 6 months)	$	5,782
2025	11,391
2026	11,018
2027	10,876
2028	10,873
Thereafter	31,695
	$	81,635