Consumers Energy Company Consolidated Statements of Changes in Equity (Unaudited) - USD ($) $ in Millions	Total	Common Stock	Other Paid-in Capital	Accumulated Other Comprehensive Loss	Retirement benefits liability	Retained Earnings	Cumulative Preferred Stock	Consumers Energy Company	Consumers Energy Company Common Stock	Consumers Energy Company Other Paid-in Capital	Consumers Energy Company Accumulated Other Comprehensive Loss	Consumers Energy Company Retirement benefits liability	Consumers Energy Company Retained Earnings	Consumers Energy Company Cumulative Preferred Stock
Total Equity at Beginning of Period at Dec. 31, 2020	$ 6,077	$ 3	$ 5,365	$ (86)	$ (80)	$ 214		$ 8,556	$ 841	$ 6,024	$ (36)	$ (36)	$ 1,690	$ 37
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholder contribution										275
Amortization of net actuarial loss	4				4			1				1
Net Income	513					525		526					526
Dividends declared on common stock						(252)							(380)
Dividends declared on preferred stock						0							(1)
Total Equity at End of Period at Jun. 30, 2021	6,366	3	5,389	(82)	(77)	487	$ 0	8,977	841	6,299	(35)	(35)	1,835	37
Total Equity at Beginning of Period at Mar. 31, 2021	6,302	3	5,371	(84)	(79)	437		8,766	841	6,174	(36)	(36)	1,750	37
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholder contribution										125
Amortization of net actuarial loss	3				3			1				1
Net Income	171					176		190					190
Dividends declared on common stock						(126)							(104)
Dividends declared on preferred stock						0							(1)
Total Equity at End of Period at Jun. 30, 2021	6,366	3	5,389	(82)	(77)	487	0	8,977	841	6,299	(35)	(35)	1,835	37
Total Equity at Beginning of Period at Dec. 31, 2021	7,188	3	5,406	(59)	(56)	1,057		9,279	841	6,599	(32)	(32)	1,834	37
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholder contribution										685
Amortization of net actuarial loss	2				2			1				1
Net Income	487					501		556					556
Dividends declared on common stock						(267)							(433)
Dividends declared on preferred stock						(5)							(1)
Total Equity at End of Period at Jun. 30, 2022	7,471	3	5,417	(52)	(52)	1,286	224	10,087	841	7,284	(31)	(31)	1,956	37
Total Equity at Beginning of Period at Mar. 31, 2022	7,405	3	5,406	(54)	(53)	1,275		9,838	841	7,049	(31)	(31)	1,942	37
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholder contribution										235
Amortization of net actuarial loss	1				1			0				0
Net Income	142					148		173					173
Dividends declared on common stock						(134)							(158)
Dividends declared on preferred stock						(3)							(1)
Total Equity at End of Period at Jun. 30, 2022	$ 7,471	$ 3	$ 5,417	$ (52)	$ (52)	$ 1,286	$ 224	$ 10,087	$ 841	$ 7,284	$ (31)	$ (31)	$ 1,956	$ 37