XML 164 R123.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
Cash And Cash Equivalents (Schedule Of Cash And Cash Equivalents, Including Restricted Amounts) (Details) - USD ($)
$ in Millions
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Cash and Cash Equivalents [Line Items]        
Cash and cash equivalents $ 140 $ 153    
Restricted cash and cash equivalents 17 21    
Other non‑current assets 0 1    
Cash and cash equivalents, including restricted amounts 157 175 $ 204 $ 257
Consumers Energy Company        
Cash and Cash Equivalents [Line Items]        
Cash and cash equivalents 11 39    
Restricted cash and cash equivalents 17 17    
Cash and cash equivalents, including restricted amounts $ 28 $ 56 $ 65 $ 152