The net carrying amount of intangibles and goodwill was $923 million at June 30, 2026 and $941 million at December 31, 2025. The gross carrying amount and accumulated amortization of each type of intangible asset and goodwill are presented in the table below.


	June 30, 2026				December 31, 2025
(in thousands)	Gross Carrying Amount		Accumulated Amortization		Gross Carrying Amount		Accumulated Amortization
Amortizing intangible assets
Customer bases	$	399,920	$	48,247	$	403,310	$	37,626
Formulas and technology	90,820		19,639		90,820		14,745
Trademarks and trade names	31,020		5,074		31,020		3,976
Backlog	19,870		2,981		19,870		1,036
Water rights	29,392				29,392
Goodwill	428,101				424,127
	$	999,123	$	75,941	$	998,539	$	57,383

Of the total intangibles (net of amortization) and goodwill, $124 million is attributable to the petroleum additives segment and $799 million is attributable to the specialty materials segment. The change in the gross carrying amount between December 31, 2025 and June 30, 2026 is due to measurement period adjustments related to the Calca acquisition and foreign currency fluctuation on goodwill in the petroleum additives segment. See Note 2 for further information on the intangibles and goodwill obtained with the Calca acquisition. There is no accumulated goodwill impairment.


Second quarter ended June 30, 2026	$	9,259
Six months ended June 30, 2026	18,573
Second quarter ended June 30, 2025	6,351
Six months ended June 30, 2025	12,702

Estimated amortization expense for the remainder of 2026, as well as estimated annual amortization expense related to our intangible assets for the next five years, is expected to be (in thousands):

We amortize the formulas and technology over a period of 8 to 20 years, the customer bases over 9 to 20 years, the trademarks and trade names over 5 to 15 years and the backlog over 5 years.