Regulatory Matters (Schedule Of The Components Of Regulatory Assets and Liabilities) (Details) (USD $) In Millions, unless otherwise specified							12 Months Ended		12 Months Ended					12 Months Ended		12 Months Ended		12 Months Ended		12 Months Ended						12 Months Ended						12 Months Ended																12 Months Ended								12 Months Ended				12 Months Ended				12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013 Consumers Energy Company [Member]	Dec. 31, 2012 Consumers Energy Company [Member]	Dec. 31, 2013 Cost Of Removal [Member] Consumers Energy Company [Member]	Dec. 31, 2012 Cost Of Removal [Member] Consumers Energy Company [Member]	Dec. 31, 2013 Renewable Energy Plan [Member] Consumers Energy Company [Member]	Dec. 31, 2012 Renewable Energy Plan [Member] Consumers Energy Company [Member]	Dec. 31, 2013 Income Taxes, Net [Member] Consumers Energy Company [Member]	Dec. 31, 2012 Income Taxes, Net [Member] Consumers Energy Company [Member]	Dec. 31, 2013 Postretirement Benefits [Member] Consumers Energy Company [Member]	Dec. 31, 2013 ARO [Member] Consumers Energy Company [Member]	Dec. 31, 2012 ARO [Member] Consumers Energy Company [Member]	Dec. 31, 2013 Renewable Energy Grant [Member] Consumers Energy Company [Member]	Jan. 31, 2013 Renewable Energy Grant [Member] Consumers Energy Company [Member]	Dec. 31, 2013 DOE Settlement [Member] Consumers Energy Company [Member]	Dec. 31, 2012 DOE Settlement [Member] Consumers Energy Company [Member]	Dec. 31, 2013 Energy Optimization Plan [Member] Consumers Energy Company [Member]	Dec. 31, 2012 Energy Optimization Plan [Member] Consumers Energy Company [Member]	Dec. 31, 2013 Other Regulatory Liabilities [Member] Consumers Energy Company [Member]	Dec. 31, 2012 Other Regulatory Liabilities [Member] Consumers Energy Company [Member]	Dec. 31, 2013 Postretirement Benefits [Member] Consumers Energy Company [Member]		Dec. 31, 2012 Postretirement Benefits [Member] Consumers Energy Company [Member]		Dec. 31, 2013 Costs Of Electric Generating Units To Be Retired And Securitized [Member] Consumers Energy Company [Member]		Dec. 31, 2013 Manufactured Gas Plant [Member] Consumers Energy Company [Member]		Dec. 31, 2012 Manufactured Gas Plant [Member] Consumers Energy Company [Member]		Dec. 31, 2013 Other Securitized Costs [Member] Consumers Energy Company [Member]		Dec. 31, 2012 Other Securitized Costs [Member] Consumers Energy Company [Member]		Dec. 31, 2013 ARO [Member] Consumers Energy Company [Member]		Dec. 31, 2012 ARO [Member] Consumers Energy Company [Member]		Dec. 31, 2013 Unamortized Debt Costs [Member] Consumers Energy Company [Member]		Dec. 31, 2012 Unamortized Debt Costs [Member] Consumers Energy Company [Member]		Dec. 31, 2013 Gas Storage Inventory Adjustments [Member] Consumers Energy Company [Member]		Dec. 31, 2012 Gas Storage Inventory Adjustments [Member] Consumers Energy Company [Member]		Dec. 31, 2013 Energy Optimization Plan Incentive [Member] Consumers Energy Company [Member]		Dec. 31, 2012 Energy Optimization Plan Incentive [Member] Consumers Energy Company [Member]		Dec. 31, 2013 Major Maintenance [Member] Consumers Energy Company [Member]		Dec. 31, 2012 Major Maintenance [Member] Consumers Energy Company [Member]		Dec. 31, 2013 Cancelled Coal-Fueled Plant Costs [Member] Consumers Energy Company [Member]		Dec. 31, 2012 Cancelled Coal-Fueled Plant Costs [Member] Consumers Energy Company [Member]		Dec. 31, 2013 Gas Revenue Decoupling Mechanism [Member] Consumers Energy Company [Member]		Dec. 31, 2012 Gas Revenue Decoupling Mechanism [Member] Consumers Energy Company [Member]		Dec. 31, 2013 Other Regulatory Assets [Member] Consumers Energy Company [Member]		Dec. 31, 2012 Other Regulatory Assets [Member] Consumers Energy Company [Member]
Regulatory Matters [Line Items]
Regulatory Current Asset, End Date for Recovery																																																2014	[1]							2014	[2]			2014	[1]			2014	[2]
Noncurrent Regulatory Asset Recovery End Date																										2029	[2]					2016	[2]															2015	[1]							2015	[2]			2014	[1]
Current Regulatory Liability Recovery End Date									2014					2014		2013				2014
Noncurrent Regulatory Liability, Recovery End Date							2028							2043				2015
Regulatory assets, current	$ 40	$ 35	$ 40	$ 35																																												$ 17	[1]	$ 15	[1]					$ 5	[2]	$ 4	[2]	$ 17	[1]	$ 16	[1]	$ 1	[2]
Regulatory assets, noncurrent	1,530	2,287	1,530	2,287																		634	[3]	1,700	[3]	362	[2]	148	[4]	152	[4]	129	[2]	192	[2]	129	[4]	123	[4]	74	[4]	55	[4]	23	[4]	15	[4]	18	[1]	17	[1]	10	[2]	5	[2]	2	[2]	7	[2]			17	[1]	1	[2]	4	[2]
Total regulatory asset			1,570	2,322
Regulatory liabilities, current	67	25	67	25					64					2			23			1	2
Regulatory liabilities, noncurrent	2,215	2,101	2,215	2,101	1,599	1,441	159	175	157	336	98	93	103	65				31	34	13	12
Total regulatory liabilities			$ 2,282	$ 2,126											$ 69

[1] These regulatory assets have arisen from alternative revenue programs and are not associated with incurred costs or capital investments. Therefore, the MPSC has provided for recovery without a return.

[2] These regulatory assets either are included in rate base (or are expected to be included, for costs incurred subsequent to the most recently approved rate case), thereby providing a return on expenditures, or provide a specific return on investment authorized by the MPSC.

[3] This regulatory asset is offset partially by liabilities. The net amount is included in rate base, thereby providing a return.

[4] These regulatory assets represent incurred costs for which the MPSC has provided, or Consumers expects, recovery without a return on investment.