Note 1 - General and Basis of Presentation (Tables)

9 Months Ended

Sep. 30, 2021

Notes Tables

Schedule of Recognized Identified Assets Acquired and Liabilities Assumed [Table Text Block]

Cash and cash equivalents and restricted cash	$	10.9
Trade receivables and others (1)		8.6
Deferred income taxes		22.4
Property, plant and equipment and construction-in-process		152.0
Intangible assets (2)		191.6
Goodwill (3)		66.6
Total assets acquired	$	452.1
Accounts payable, accrued expenses and others	$	6.6
Finance liability (4)		258.4
Asset retirement obligation		5.3
Total liabilities assumed	$	270.3
Total assets acquired, and liabilities assumed, net	$	181.8

Business Acquisition, Pro Forma Information [Table Text Block]

	Pro forma for the Three Months Ended September 30,				Pro forma for the Nine Months Ended September 30,
	2021		2020		2021		2020
	(Dollars in millions)				(Dollars in millions)
Electricity revenues	$	144.7	$	140.5	$	449.1	$	438.4
Total revenues	$	160.8	$	175.8	$	499.7	$	569.1
Net income	$	18.5	$	18.0	$	50.4	$	64.3

Schedule of Cash and Cash Equivalents [Table Text Block]

	September 30,		December 31,		September 30,
	2021		2020		2020
	(Dollars in thousands)
Cash and cash equivalents	$	267,802	$	448,252	$	197,309
Restricted cash and cash equivalents		88,498		88,526		92,233
Total Cash and cash equivalents and restricted cash and cash equivalents	$	356,300	$	536,778	$	289,542

Finance Liabilities [Table Text Block]

	September 30,		December 31,
	2021		2020
	(Dollars in thousands)
Current Finance Liabilities:
Finance lease liabilities	$	3,019	$	3,169
Finance liability		10,835		—
Total Current Finance Liabilities	$	13,854	$	3,169
Long-term Finance Liabilities:
Finance lease liabilities	$	4,693	$	9,104
Finance liability		242,029		—
Total Long-term Finance Liabilities	$	246,722	$	9,104

Schedules of Concentration of Risk, by Risk Factor [Table Text Block]

	Three Months Ended September 30,						Nine Months Ended September 30,
	2021			2020			2021			2020
Sierra Pacific Power Company and Nevada Power Company		15.8	%		15.4	%		18.7	%		17.1	%
Southern California Public Power Authority (“SCPPA”)		21.3			19.5			23.9			19.8
Kenya Power and Lighting Co. Ltd. ("KPLC")		16.1			18.2			16.3			16.5

Accounts Receivable, Allowance for Credit Loss [Table Text Block]

	Three Months Ended September 30,					Nine Months Ended September 30,
	2021			2020		2021			2020
	(Dollars in thousands)					(Dollars in thousands)
Beginning balance of the allowance for expected credit losses	$	419		$	779	$	597		$	755
Change in the provision for expected credit losses for the period		(166	)		—		(344	)		24
Ending balance of the allowance for expected credit losses	$	253		$	779	$	253		$	779

Contract with Customer, Contract Asset, Contract Liability, and Receivable [Table Text Block]

	September 30,			December 31,
	2021			2020
	(Dollars in thousands)
Contract assets (*)	$	9,324		$	24,544
Contract liabilities (*)	$	(15,829	)	$	(11,179	)

Operating Lease, Lease Income [Table Text Block]

	Three Months Ended September 30,				Nine Months Ended September 30,
	2021		2020		2021		2020
	(Dollars in thousands)				(Dollars in thousands)
Lease income relating to lease payments from operating leases	$	123,688	$	108,619	$	362,548	$	347,778