Goodwill and other intangible assets

3 Months Ended

Mar. 31, 2023

Goodwill and Intangible Assets Disclosure [Abstract]

The changes in the carrying amount of goodwill were as follows:


	Balance at January 1, 2023		Goodwill Acquired During the Year		Measurement Period Adjustments		Balance at March 31, 2023
	(In thousands)
Natural gas distribution	$	345,736	$	—	$	—	$	345,736
Construction materials and contracting	274,540		—		—		274,540
Construction services	143,224		—		—		143,224
Total	$	763,500	$	—	$	—	$	763,500


	Balance at January 1, 2022		Goodwill Acquired During the Year		Measurement Period Adjustments		Balance at March 31, 2022
	(In thousands)
Natural gas distribution	$	345,736	$	—	$	—	$	345,736
Construction materials and contracting	276,426		—		(2,124)		274,302
Construction services	143,224		—		—		143,224
Total	$	765,386	$	—	$	(2,124)	$	763,262


	Balance at January 1, 2022		Goodwill Acquired During the Year		Measurement Period Adjustments		Balance at December 31, 2022
	(In thousands)
Natural gas distribution	$	345,736	$	—	$	—	$	345,736
Construction materials and contracting	276,426		238		(2,124)		274,540
Construction services	143,224		—		—		143,224
Total	$	765,386	$	238	$	(2,124)	$	763,500

Other amortizable intangible assets were as follows:


	March 31, 2023		March 31, 2022		December 31, 2022
	(In thousands)
Customer relationships	$	28,990	$	28,990	$	28,990
Less accumulated amortization	14,680		10,846		13,724
	14,310		18,144		15,266
Noncompete agreements	4,331		4,591		4,591
Less accumulated amortization	3,405		3,016		3,529
	926		1,575		1,062
Other	2,479		6,969		5,280
Less accumulated amortization	1,381		5,299		4,076
	1,098		1,670		1,204
Total	$	16,334	$	21,389	$	17,532

The previous tables include goodwill and intangible assets associated with the business combinations completed during 2022. For more information related to these business combinations, see Note 9.

Amortization expense for amortizable intangible assets for both the three months ended March 31, 2023 and 2022, was $1.2 million. Estimated amortization expense for identifiable intangible assets as of March 31, 2023, was:


	Remainder of 2023		2024		2025		2026		2027		Thereafter
	(In thousands)
Amortization expense	$	3,393	$	4,249	$	2,200	$	1,782	$	1,759	$	2,951