Long-Term Debt and Liquidity Matters - Future Principal Payments (Details) $ in Thousands	Dec. 31, 2018 USD ($)
Pinnacle West
Principal payments due on long-term debt
2019	$ 500,000
2020	700,000
2021	0
2022	0
2023	0
Thereafter	3,976,125
Total	5,176,125
ARIZONA PUBLIC SERVICE COMPANY
Principal payments due on long-term debt
2019	500,000
2020	250,000
2021	0
2022	0
2023	0
Thereafter	3,976,125
Total	$ 4,726,125

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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