Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Allowance for doubtful accounts receivable	$ 20	$ 20
Allowances for doubtful notes receivable	$ 24	$ 20
Common stock authorized (in shares)	350,000,000	350,000,000
Common stock outstanding (in shares)	283,400,000	281,600,000
Consumers Energy Company
Allowance for doubtful accounts receivable	$ 20	$ 20
Common stock authorized (in shares)	125,000,000	125,000,000
Common stock outstanding (in shares)	84,100,000	84,100,000