XML 40 R31.htm IDEA: XBRL DOCUMENT v3.20.2
Fair Value Measurements (Tables)
9 Months Ended
Sep. 30, 2020
Fair Value Disclosures [Abstract]  
Schedule of Fair Value and Carrying Amount of PRM Financial Instruments [Table Text Block] The following table summarizes the carrying amount and fair value of the Company's financial instruments at September 30, 2020 and December 31, 2019.
September 30,December 31,
 20202019
(In millions)Carrying Amount Fair
Value
Carrying Amount  Fair
Value
Classification
Long-term Debt (including Long-term Debt due within one year):    
OG&E Senior Notes$3,349.0 $4,116.5 $3,050.3 $3,500.4 Level 2
OG&E Industrial Authority Bonds$135.4 $135.4 $135.4 $135.4 Level 2
Tinker Debt$9.5 $10.6 $9.5 $10.0 Level 3