Other Income and Other Expense (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Fee income	$ 6	$ 9	$ 8
All other	2	1	3
Total other income	8	10	11
Civic and political expenditures	(21)	(10)	(14)
Donations	(23)	(1)	(15)
Loss on reacquired and extinguished debt	(18)		(20)
Unrealized investment loss	(5)
All other	(8)	(6)	(6)
Total other expense	(75)	(17)	(55)
Consumers Energy Company [Member]
Fee income	6	9	8
Gain on CMS Energy common stock		9
All other	2	1	2
Total other income	8	19	10
Civic and political expenditures	(21)	(10)	(14)
Donations	(23)	(1)	(15)
Unrealized investment loss	(4)
All other	(7)	(6)	(6)
Total other expense	$ (55)	$ (17)	$ (35)