Note 5. Goodwill and Intangible Assets (Details) - Other Intangible Assets - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Other Intangible Assets, Net [Abstract]
Intangible assets, gross	$ 112,230	$ 111,608
Intangible assets, accumulated amortization	(47,687)	(37,446)
Intangible assets, net	64,543	74,162
Amortization of intangible assets	10,200	9,900	$ 8,300
Other Intangible Assets, Future Amortization Expense, Current and Five Succeeding Fiscal Years [Abstract]
Other Intangible Assets, Amortization Expense, Next Twelve Months	10,498
Other Intangible Assets, Amortization Expense, Year Two	10,496
Other Intangible Assets, Amortization Expense, Year Three	10,471
Other Intangible Assets, Amortization Expense, Year Four	10,187
Other Intangible Assets, Amortization Expense, Year Five	10,057
Other Intangible Assets, Amortization Expense, Thereafter	12,834
Finite-Lived Intangible Assets, Net	64,543
Developed technology [Member]
Other Intangible Assets, Net [Abstract]
Intangible assets, gross	97,964	97,714
Intangible assets, accumulated amortization	(42,344)	(33,093)
Intangible assets, net	55,620	64,621
Power purchase agreements [Member]
Other Intangible Assets, Net [Abstract]
Intangible assets, gross	6,486	6,486
Intangible assets, accumulated amortization	(972)	(648)
Intangible assets, net	5,514	5,838
Patents [Member]
Other Intangible Assets, Net [Abstract]
Intangible assets, gross	7,780	7,408
Intangible assets, accumulated amortization	(4,371)	(3,705)
Intangible assets, net	$ 3,409	$ 3,703