| Document and Entity Information | Jan. 09, 2020 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Jan. 9, 2020 |
| Entity Registrant Name | MOLINA HEALTHCARE, INC. |
| Entity Incorporation, State or Country Code | DE |
| Entity File Number | 001-31719 |
| Entity Tax Identification Number | 13-4204626 |
| Entity Address, Address Line One | 200 Oceangate, Suite 100 |
| Entity Address, City or Town | Long Beach |
| Entity Address, State or Province | CA |
| Entity Address, Postal Zip Code | 90802 |
| City Area Code | 562 |
| Local Phone Number | 435-3666 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | false |
| Entity Central Index Key | 0001179929 |
| Title of 12(b) Security | Common Stock, $0.001 Par Value |
| Trading Symbol | MOH |
| Security Exchange Name | NYSE |
