Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Net income	$ 140	$ 93	$ 381	$ 292
Retirement Benefits Liability
Amortization of net actuarial loss, net of tax of $- for all periods	1	1	2	1
Amortization of prior service credit	(1)	0	(1)	0
Investments
Unrealized gain (loss) on investments	0	0	(1)	1
Other Comprehensive Income	0	1	0	2
Comprehensive Income	140	94	381	294
Comprehensive Income Attributable to Noncontrolling Interests	1	1	1	1
Comprehensive Income Attributable to CMS Energy	139	93	380	293
Consumers Energy Company
Net income	152	104	394	315
Retirement Benefits Liability
Amortization of net actuarial loss, net of tax of $- for all periods	0	1	1	1
Investments
Unrealized gain (loss) on investments	0	0	(1)	2
Reclassification adjustments included in net income, net of tax	0	0	0	(8)
Other Comprehensive Income	0	1	0	(5)
Comprehensive Income	$ 152	$ 105	$ 394	$ 310