INTANGIBLE ASSETS, NET (Tables)

3 Months Ended

Mar. 31, 2022

Goodwill and Intangible Assets Disclosure [Abstract]

Summary of Intangible Assets by Major Class

The following tables summarize the gross carrying amounts and accumulated amortization of intangible assets by major class:
	March 31, 2022
	Gross		Accumulated Amortization		Net
	(thousands of dollars)
Customer relationships	$	16,852	$	(8,426)	$	8,426
Non-compete agreements	94		(94)		—
Licenses and permits	1,471		(829)		642
Developed technology	6,131		(4,598)		1,533
Total	$	24,548	$	(13,947)	$	10,601

	December 31, 2021
	Gross		Accumulated Amortization		Net
	(thousands of dollars)
Customer relationships	$	16,852	$	(8,145)	$	8,707
Non-compete agreements	94		(94)		—
Licenses and permits	1,471		(808)		663
Developed technology	6,131		(4,445)		1,686
Total	$	24,548	$	(13,492)	$	11,056

Estimated Amortization Expenses for Succeeding Five Fiscal Years

Based on identified intangible assets that are subject to amortization as of March 31, 2022, we expect future amortization expenses for each period to be as follows:

	Total		Remainder of 2022		2023		2024		2025		2026		2027		Thereafter
	(thousands of dollars)
Customer relationships	$	8,426	$	843	$	1,123	$	1,123	1,123		1,123		1,123		$	1,968
Licenses and permits	642		64		86		86		86		86		86		148
Developed technology	1,533		460		613		460		—		—		—		—
Total future amortization expense	$	10,601	$	1,367	$	1,822	$	1,669	$	1,209	$	1,209	$	1,209	$	2,116