Income Taxes (Schedule Of Effective Income Rate Reconciliation) (Details)	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
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	5.50%	5.40%
TCJA excess deferred taxes	(7.20%)	(5.90%)
Production tax credits	(5.10%)	(5.10%)
Accelerated flow-through of regulatory tax benefits	(4.30%)	(3.30%)
Other, net	0.00%	0.10%
Effective tax rate	9.90%	12.20%
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	5.20%	5.20%
TCJA excess deferred taxes	(6.00%)	(4.90%)
Production tax credits	(3.80%)	(3.20%)
Accelerated flow-through of regulatory tax benefits	(3.60%)	(3.00%)
Other, net	(0.40%)	(0.50%)
Effective tax rate	12.40%	14.60%