Income Taxes - Reconciliation of Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Tabular reconciliation of the total amounts of unrecognized tax benefits, excluding interest and penalties, at the beginning and end of the year
Total unrecognized tax benefits, beginning of the year	$ 40,731	$ 41,966	$ 36,075
Additions for tax positions of the current year	3,373	3,436	2,937
Additions for tax positions of prior years	1,843	2,696	4,783
Reductions for tax positions of prior years for:
Changes in judgment	(2,078)	(1,764)	(1,829)
Settlements with taxing authorities	0	0	0
Lapses of applicable statute of limitations	(434)	(5,603)	0
Total unrecognized tax benefits, end of the year	43,435	40,731	41,966
ARIZONA PUBLIC SERVICE COMPANY
Tabular reconciliation of the total amounts of unrecognized tax benefits, excluding interest and penalties, at the beginning and end of the year
Total unrecognized tax benefits, beginning of the year	40,731	41,966	36,075
Additions for tax positions of the current year	3,373	3,436	2,937
Additions for tax positions of prior years	1,843	2,696	4,783
Reductions for tax positions of prior years for:
Changes in judgment	(2,078)	(1,764)	(1,829)
Settlements with taxing authorities	0	0	0
Lapses of applicable statute of limitations	(434)	(5,603)	0
Total unrecognized tax benefits, end of the year	$ 43,435	$ 40,731	$ 41,966