Goodwill and other intangible assets

3 Months Ended

Mar. 31, 2022

Goodwill and Intangible Assets Disclosure [Abstract]

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


	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, 2021		Goodwill Acquired During the Year		Measurement Period Adjustments		Balance at March 31, 2021
	(In thousands)
Natural gas distribution	$	345,736	$	—	$	—	$	345,736
Construction materials and contracting	226,003		—		—		226,003
Construction services	143,224		—		—		143,224
Total	$	714,963	$	—	$	—	$	714,963


	Balance at January 1, 2021		Goodwill Acquired During the Year		Measurement Period Adjustments		Balance at December 31, 2021
	(In thousands)
Natural gas distribution	$	345,736	$	—	$	—	$	345,736
Construction materials and contracting	226,003		50,640		(217)		276,426
Construction services	143,224		—		—		143,224
Total	$	714,963	$	50,640	$	(217)	$	765,386

Other amortizable intangible assets were as follows:


	March 31, 2022		March 31, 2021		December 31, 2021
	(In thousands)
Customer relationships	$	28,990	$	28,836	$	29,740
Less accumulated amortization	10,846		7,792		10,650
	18,144		21,044		19,090
Noncompete agreements	4,591		3,941		4,591
Less accumulated amortization	3,016		2,441		2,856
	1,575		1,500		1,735
Other	6,969		11,957		12,601
Less accumulated amortization	5,299		10,540		10,848
	1,670		1,417		1,753
Total	$	21,389	$	23,961	$	22,578

The previous tables include goodwill and intangible assets associated with the business combinations completed during 2021. For more information related to these business combinations, see Note 10.

Amortization expense for amortizable intangible assets for the three months ended March 31, 2022 and 2021, was $1.2 million and $1.5 million, respectively. Estimated amortization expense for identifiable intangible assets as of March 31, 2022, was:


	Remainder of 2022		2023		2024		2025		2026		Thereafter
	(In thousands)
Amortization expense	$	3,630	$	4,470	$	4,200	$	2,206	$	1,716	$	5,167