Goodwill and Intangible Assets (Tables)

3 Months Ended

Mar. 31, 2020

Goodwill And Intangible Assets Disclosure [Abstract]

Summary of Changes in Carrying Amount of Intangible Assets

Changes in the carrying amount of intangible assets are as follows:

	March 31, 2020
	Gross Carrying Amount		Accumulated Amortization			Amortization			Intangible Assets, net		Weighted Average Amortization Period
	(in thousands)
Stream mitigation rights	$	2,328	$	(971	)	$	(20	)	$	1,337	17 years
Customer relationships		51,537		(19,264	)		(1,879	)		30,394	4 years
Intangible assets, net	$	53,865	$	(20,235	)	$	(1,899	)	$	31,731	5 years
	December 31, 2019
	Gross Carrying Amount		Accumulated Amortization			Impairment			Intangible Assets, net		Weighted Average Amortization Period
	(in thousands)
Stream mitigation rights	$	4,170	$	(971	)	$	(1,842	)	$	1,357	17 years
Customer relationships		73,000		(19,264	)		(21,463	)		32,273	4 years
Intangible assets, net	$	77,170	$	(20,235	)	$	(23,305	)	$	33,630	5 years

Summary of Estimated Amortization Expense Related to Intangible Assets

The estimated amortization expense related to intangible assets for the five succeeding years is as follows:

	Amortization
	(in thousands)
2020	$	5,489
2021		7,388
2022		7,388
2023		7,388
2024		3,125
Thereafter		953
Total	$	31,731