Contractual interest rate for funds borrowed, under the debt agreement.

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Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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The parent entity's interest in net assets of the subsidiary, expressed as a percentage.

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The remaining balance of debt issuance expenses that were capitalized and are being amortized against income over the lives of the respective bond issues. This does not include the amounts capitalized as part of the cost of the utility plant or asset.

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Long-Term Debt (Narrative) (Details) - USD ($) $ in Millions	1 Months Ended
	Mar. 31, 2021	Jun. 30, 2021	Dec. 31, 2020	Jul. 31, 2000
Debt Instrument [Line Items]
Unamortized debt issuance cost		$ 26	$ 28
RS Cogen
Debt Instrument [Line Items]
Noncontrolling Interest, Ownership Percentage by Parent		50.00%
Senior Notes \| 8.73% Senior Notes Due 2022
Debt Instrument [Line Items]
Stated interest rate (percent)		8.73%
Senior Notes \| Term Loan Due Twenty Twenty Six
Debt Instrument [Line Items]
Maximum borrowing capacity		$ 23
Stated interest rate (percent)		0.20%
Debt instrument term	5 years
Senior Notes \| Term Loan Due Twenty Twenty Six \| Taiwan Chlorine Industries, Ltd.
Debt Instrument [Line Items]
Noncontrolling Interest, Ownership Percentage by Parent		60.00%
Line of Credit \| 8.73% Senior Notes Due 2022
Debt Instrument [Line Items]
Maximum borrowing capacity				$ 75
Stated interest rate (percent)		8.73%
Line of Credit \| 8.73% Senior Notes Due 2022 \| RS Cogen
Debt Instrument [Line Items]
Noncontrolling Interest, Ownership Percentage by Parent		50.00%