Investment in Unconsolidated Affiliate and Related Party Transactions (Tables)

12 Months Ended

Dec. 31, 2019

Equity Method Investments and Joint Ventures [Abstract]

Summarized Balance Sheet Financial Information, Equity Method Investment [Table Text Block]

Summarized unaudited financial information for 100 percent of Enable is presented below as of December 31, 2019 and 2018 and for the years ended December 31, 2019, 2018 and 2017.

	December 31,
Balance Sheet	2019		2018
(In millions)
Current assets	$	389	$	449
Non-current assets	$	11,877	$	11,995
Current liabilities	$	780	$	1,615
Non-current liabilities	$	4,077	$	3,211

Summarized Income Statement Financial Information, Equity Method Investment [Table Text Block]

	Year Ended December 31,
Income Statement	2019		2018		2017
(In millions)
Total revenues	$	2,960	$	3,431	$	2,803
Cost of natural gas and NGLs	$	1,279	$	1,819	$	1,381
Operating income	$	569	$	648	$	528
Net income	$	360	$	485	$	400

Reconciliation of Equity in Earnings of Unconsolidated Affiliates [Table Text Block]

The following table reconciles OGE Energy's equity in earnings of unconsolidated affiliates for the years ended December 31, 2019, 2018 and 2017.

	Year Ended December 31,
(In millions)	2019			2018			2017
Enable net income	$	360.0		$	485.3		$	400.3
OGE Energy's percent ownership at period end	25.5		%	25.6		%	25.7		%
OGE Energy's portion of Enable net income	$	91.8		$	124.4		$	102.7
Amortization of basis difference and dilution recognition (A)	22.1			28.4			28.5
Equity in earnings of unconsolidated affiliates	$	113.9		$	152.8		$	131.2

(A) Includes loss on dilution, net of proportional basis difference recognition.

Reconciliation of Basis Difference [Table Text Block]

The following table reconciles the difference between OGE Energy's investment in Enable and its underlying equity in the net assets of Enable (basis difference) from December 31, 2018 to December 31, 2019.

(In millions)
Basis difference at December 31, 2018	$	680.3
Amortization of basis difference (A)	(27.8)
Basis difference at December 31, 2019	$	652.5

(A) Includes proportional basis difference recognition due to dilution.

Schedule of Related Party Transactions [Table Text Block]

The following table summarizes related party transactions between OG&E and Enable during the years ended December 31, 2019, 2018 and 2017.

	Year Ended December 31,
(In millions)	2019		2018		2017
Operating revenues:
Electricity to power electric compression assets	$	15.9	$	16.3	$	14.0
Cost of sales:
Natural gas transportation services	$	41.2	$	37.9	$	35.0
Natural gas (sales) purchases	$	(6.0)	$	(3.2)	$	(2.1)