Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Net income	$ 207	$ 169	$ 514	$ 550
Retirement Benefits Liability
Amortization of net actuarial loss, net of tax of $- for all periods	0	1	2	3
Amortization of prior service credit	0	0	(1)	(1)
Investments
Unrealized loss on investments	0	0	0	(1)
Reclassification adjustments included in net income	0	1	0	1
Derivatives
Unrealized loss on derivative instruments, net of tax of $-, $-, $(1), and $-	0		(3)
Unrealized loss on derivative instruments, net of tax of $-, $-, $(1), and $-		0		0
Other Comprehensive Income (Loss)	0	2	(2)	2
Comprehensive Income	207	171	512	552
Comprehensive Income Attributable to Noncontrolling Interests	0	0	1	1
Comprehensive Income Attributable to CMS Energy	207	171	511	551
Consumers Energy Company
Net income	213	180	537	574
Retirement Benefits Liability
Amortization of net actuarial loss, net of tax of $- for all periods	0	1	1	2
Investments
Unrealized loss on investments	0	0	0	(1)
Reclassification adjustments included in net income	0	1	0	1
Derivatives
Other Comprehensive Income (Loss)	0	2	1	2
Comprehensive Income	$ 213	$ 182	$ 538	$ 576