Summary of Significant Accounting Policies - Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Cash and Cash Equivalents [Line Items]
Income taxes, net of refunds	$ 229	$ (3,019)	$ 12,535
Interest, net of amounts capitalized	227,584	216,951	218,664
Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract]
Accrued capital expenditures	167,733	113,502	141,297
Dividends declared but not paid	95,988	93,531	87,982
Arizona Public Service Company
Cash and Cash Equivalents [Line Items]
Income taxes, net of refunds	19,783	41,176	(15,042)
Interest, net of amounts capitalized	217,749	206,328	204,261
Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract]
Accrued capital expenditures	167,657	113,502	141,297
Dividends declared but not paid	$ 96,000	$ 93,500	$ 88,000