Income Taxes (Schedule Of Effective Income Rate Reconciliation) (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Income Taxes [Line Items]
U.S. federal income tax rate	21.00%	21.00%
Increase (decrease) in income taxes from:
State and local income taxes, net of federal effect	2.60%	5.50%
Production tax credits	(4.40%)	(5.10%)
TCJA excess deferred taxes	(4.00%)	(7.20%)
Accelerated flow-through of regulatory tax benefits	0.00%	(4.30%)
Other, net	0.30%	0.00%
Effective tax rate	15.50%	9.90%
Consumers Energy Company
Income Taxes [Line Items]
U.S. federal income tax rate	21.00%	21.00%
Increase (decrease) in income taxes from:
State and local income taxes, net of federal effect	2.40%	5.20%
Production tax credits	(4.10%)	(3.80%)
TCJA excess deferred taxes	(3.60%)	(6.00%)
Accelerated flow-through of regulatory tax benefits	0.00%	(3.60%)
Other, net	(0.40%)	(0.40%)
Effective tax rate	15.30%	12.40%
Consumers Energy Company | Non-Michigan Jurisdiction
Increase (decrease) in income taxes from:
Reversal of tax reserve	$ 13