Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Accounts receivable and accrued revenue ALLOWANCE	$ 20	$ 20
Accounts and notes receivable ALLOWANCE	$ 23	$ 20
Common Stock, Shares Authorized (in shares)	350,000,000.0	350,000,000.0
Common Stock, Shares, Outstanding	283,300,000	281,600,000
Consumers Energy Company
Accounts receivable and accrued revenue ALLOWANCE	$ 20	$ 20
Common Stock, Shares Authorized (in shares)	125,000,000	125,000,000
Common Stock, Shares, Outstanding	84,100,000	84,100,000