CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
PROPERTY, PLANT AND EQUIPMENT
Accumulated depreciation of Palo Verde sale leaseback	$ 256,884	$ 253,014
Accumulated amortization on intangible assets	737,694	698,500
Accumulated amortization on nuclear fuel	$ 133,122	$ 137,207
EQUITY
Common stock, authorized shares (in shares)	150,000,000	150,000,000
Common stock, issued shares (in shares)	113,014,528	112,760,051
Treasury stock at cost, shares (in shares)	87,608	72,006