XML 32 R18.htm IDEA: XBRL DOCUMENT

PPAs and other definite-lived intangible assets and liabilities

12 Months Ended

Dec. 31, 2020

10. PPAs and other definite-lived intangible assets and liabilities

Other intangible assets and liabilities include PPAs, fuel supply agreements and capitalized development costs.

The following tables summarize the components of our intangible assets and other liabilities subject to amortization at December 31, 2020 and 2019:

Assets


	Other Intangible Assets, Net
	Power Purchase
	Agreements		Total
Gross balances, January 1, 2020	$	365.6	$	365.6
Write-off of fully amortized balances		(13.5)		(13.5)
Gross balances, December 31, 2020		352.1		352.1
Less: accumulated amortization		(231.8)		(231.8)
Net carrying amounts, December 31, 2020	$	120.3	$	120.3


	Other Intangible Assets, Net
	Power Purchase
	Agreements		Total
Gross balances, December 31, 2019	$	365.6	$	365.6
Less: accumulated amortization		(221.3)		(221.3)
Net carrying amounts, December 31, 2019	$	144.3	$	144.3

Liabilities


	Power Purchase and Fuel Supply Agreement Liabilities, Net
	Power Purchase		Fuel Supply
	Agreements		Agreements		Total
Gross balances, December 31, 2020	$	(28.5)	$	(12.6)	$	(41.1)
Less: accumulated amortization		16.2		6.9		23.1
Net carrying amounts, December 31, 2020	$	(12.3)	$	(5.7)	$	(18.0)


	Power Purchase and Fuel Supply Agreement Liabilities, Net
	Power Purchase		Fuel Supply
	Agreements		Agreements		Total
Gross balances, December 31, 2019	$	(28.1)	$	(12.6)	$	(40.7)
Less: accumulated amortization		14.4		6.5		20.9
Net carrying amounts, December 31, 2019	$	(13.7)	$	(6.1)	$	(19.8)

The following table presents amortization expense of intangible assets for the years ended December 31, 2020 and 2019:

The following table presents estimated future amortization expense for the next five years:

The weighted average remaining amortization period related to our intangible assets and liabilities was 8.1 years as of December 31, 2020.