Regulatory Matters - MISO Return on Equity Complaint (Details) - FERC [Member]	Jun. 30, 2020	Dec. 31, 2019
Loss Contingencies [Line Items]
FERC Authorized Return on Common Equity	10.02%	9.88%
FERC Authorized Return on Equity, Including Incentive Adder	10.52%	10.38%

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

Name:	us-gaap_LossContingenciesLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration