Intangible Assets

12 Months Ended

Dec. 31, 2021

Goodwill and Intangible Assets Disclosure [Abstract]

Intangible Assets

Intangible Assets

The Company has a coal supply agreement intangible asset which is subject to amortization based on units of production over the term of the lignite sales agreement which expires in 2032. The gross and net balances are set forth in the following table:

	Gross Carrying Amount		Accumulated Amortization		Net Balance
Balance at December 31, 2021
Coal supply agreement	$	84,200	$	(52,426)	$	31,774
Balance at December 31, 2020
Coal supply agreement	$	84,200	$	(48,870)	$	35,330

Amortization expense for intangible assets was $3.6 million and $2.6 million in 2021 and 2020, respectively.

Expected annual amortization expense of the coal supply agreement for the next five years is $3.1 million in 2022 through 2026.