Consolidated Statements Of Income - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Operating Revenue		$ 6,399	$ 6,456	$ 7,179
Operating Expenses
Fuel for electric generation		499	593	673
Purchased and interchange power		1,508	1,406	1,602
Purchased power - related parties		86	83	90
Cost of gas sold		710	961	1,493
Maintenance and other operating expenses		1,207	1,238	1,232
Depreciation and amortization		811	750	685
General taxes		281	262	252
Total operating expenses		5,102	5,293	6,027
Operating Income		1,297	1,163	1,152
Other Income (Expense)
Interest income		6	12	5
Allowance for equity funds used during construction		12	10	8
Income from equity method investees	[1]	13	14	15
Other income		8	10	11
Other expense		(75)	(17)	(55)
Total other income		(36)	29	(16)
Interest Charges
Interest on long-term debt		411	386	393
Other interest expense		29	14	17
Allowance for borrowed funds used during construction		(5)	(4)	(3)
Total interest charges		435	396	407
Income Before Income Taxes		826	796	729
Income Tax Expense		273	271	250
Net Income		553	525	479
Income Attributable to Noncontrolling Interests		2	2	2
Net Income Available to Common Stockholders		$ 551	$ 523	$ 477
Basic Earnings Per Average Common Share		$ 1.99	$ 1.90	$ 1.76
Diluted Earnings Per Average Common Share		$ 1.98	$ 1.89	$ 1.74
Consumers Energy Company [Member]
Operating Revenue		$ 6,064	$ 6,165	$ 6,800
Operating Expenses
Fuel for electric generation		393	497	567
Purchased and interchange power		1,486	1,376	1,564
Purchased power - related parties		88	83	89
Cost of gas sold		693	939	1,375
Maintenance and other operating expenses		1,090	1,149	1,146
Depreciation and amortization		803	744	678
General taxes		277	255	246
Total operating expenses		4,830	5,043	5,665
Operating Income		1,234	1,122	1,135
Other Income (Expense)
Interest income		4	11	4
Interest and dividend income - related parties		1	1	1
Allowance for equity funds used during construction		12	10	8
Other income		8	19	10
Other expense		(55)	(17)	(35)
Total other income		(30)	24	(12)
Interest Charges
Interest on long-term debt		261	252	243
Other interest expense		12	2	10
Allowance for borrowed funds used during construction		(5)	(4)	(3)
Total interest charges		268	250	250
Income Before Income Taxes		936	896	873
Income Tax Expense		320	302	306
Net Income		616	594	567
Preferred Stock Dividends		2	2	2
Net Income Available to Common Stockholders		$ 614	$ 592	$ 565

[1] Consumers had no significant equity method investments.