Consolidated Statements Of Comprehensive Income (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Net Income	$ 204	$ 144
Retirement Benefits Liability
Amortization of net actuarial loss, net of tax		1
Derivative Instruments
Reclassification adjustments included in net income, net of tax of $- and $-	1
Investments
Other Comprehensive Income (Loss)	1	1
Comprehensive Income	205	145
Consumers Energy Company [Member]
Net Income	221	162
Retirement Benefits Liability
Amortization of net actuarial loss, net of tax		1
Investments
Unrealized gain (loss) on investments, net of tax	2	4
Reclassification adjustments included in net income, net of tax		(3)
Other Comprehensive Income (Loss)	2	2
Comprehensive Income	$ 223	$ 164