Consolidated Statements Of Comprehensive Income - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Net income	$ 199	$ 164
Investments
Unrealized gain on investments, net of tax	1
Other Comprehensive Income (Loss)	1
Comprehensive Income	200	164
Consumers Energy Company [Member]
Net income	211	172
Investments
Unrealized gain on investments, net of tax	2	3
Reclassification adjustments included in net income, net of tax	(8)
Other Comprehensive Income (Loss)	(6)	3
Comprehensive Income	$ 205	$ 175