Consolidated Statements Of Comprehensive Income (Parenthetical) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Amortization of net actuarial loss TAX	$ 0	$ 0	$ 0	$ 0
Amortization of prior service credit (TAX BENEFIT)	0	0	0	0
Unrealized loss on investments (TAX BENEFIT)	0	0	0	0
Reclassification adjustments included in net income TAX (TAX BENEFIT)	0	0	0	0
Unrealized loss on derivative instruments (TAX BENEFIT)	0		(1)
Unrealized loss on derivative instruments (TAX BENEFIT)		0		0
Consumers Energy Company
Amortization of net actuarial loss TAX	0	0	0	0
Unrealized loss on investments (TAX BENEFIT)	0	0	0	0
Reclassification adjustments included in net income TAX (TAX BENEFIT)	$ 0	$ 0	$ 0	$ 0