CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
PROPERTY, PLANT AND EQUIPMENT
Accumulated depreciation of Palo Verde sale leaseback	$ 253,014	$ 249,144
Accumulated amortization on intangible assets	698,500	647,276
Accumulated amortization on nuclear fuel	$ 137,207	$ 137,330
EQUITY
Common stock, authorized shares (in shares)	150,000,000	150,000,000
Common stock, issued shares (in shares)	112,760,051	112,540,126
Treasury stock at cost, shares (in shares)	72,006	103,546
ARIZONA PUBLIC SERVICE COMPANY
PROPERTY, PLANT AND EQUIPMENT
Accumulated depreciation of Palo Verde sale leaseback	$ 253,014	$ 249,144
Accumulated amortization on intangible assets	697,366	646,142
Accumulated amortization on nuclear fuel	$ 137,207	$ 137,330