Significant Accounting Policies (Policies)	9 Months Ended
Significant Accounting Policies (Policies)	Sep. 30, 2016
Accounting Policies [Abstract]
Consolidation and Interim Financial Information	Consolidation and Interim Financial Information The consolidated financial statements include the accounts of Molina Healthcare, Inc., its subsidiaries, and variable interest entities (VIEs) in which Molina Healthcare, Inc. is considered to be the primary beneficiary. Such VIEs are insignificant to our consolidated financial position and results of operations. In the opinion of management, all adjustments considered necessary for a fair presentation of the results as of the date and for the interim periods presented have been included; such adjustments consist of normal recurring adjustments. All significant intercompany balances and transactions have been eliminated. The consolidated results of operations for the current interim period are not necessarily indicative of the results for the entire year ending December 31, 2016. The unaudited consolidated interim financial statements have been prepared under the assumption that users of the interim financial data have either read or have access to our audited consolidated financial statements for the fiscal year ended December 31, 2015. Accordingly, certain disclosures that would substantially duplicate the disclosures contained in the December 31, 2015 audited consolidated financial statements have been omitted. These unaudited consolidated interim financial statements should be read in conjunction with our December 31, 2015 audited consolidated financial statements.
Premium Revenue – Health Plans Segment	Revenue Recognition – Health Plans Segment Premium revenue is fixed in advance of the periods covered and except as described below, is not generally subject to significant accounting estimates. Premium revenues are recognized in the month that members are entitled to receive health care services, and premiums collected in advance are deferred. Certain components of premium revenue are subject to accounting estimates and fall into the following categories: Contractual Provisions That May Adjust or Limit Revenue or Profit Medicaid Medical Cost Floors (Minimums), Medical Cost Corridors, and Administrative Cost Ceilings (Maximums): A portion of our premium revenue may be returned if certain minimum amounts are not spent on defined medical care costs. In the aggregate, we recorded a liability under the terms of such contract provisions of $323 million and $214 million at September 30, 2016 and December 31, 2015, respectively, to amounts due government agencies. Approximately $298 million and $208 million of the liability accrued at September 30, 2016 and December 31, 2015, respectively, relates to our participation in Medicaid Expansion programs. In certain circumstances, the health plans may receive additional premiums if amounts spent on medical care costs exceed a defined maximum threshold. We recorded receivables of $1 million and $3 million at September 30, 2016 and December 31, 2015, respectively, relating to such provisions. Profit Sharing and Profit Ceiling: Our contracts with certain states contain profit-sharing or profit ceiling provisions under which we refund amounts to the states if our health plans generate profit above a certain specified percentage. In some cases, we are limited in the amount of administrative costs that we may deduct in calculating the refund, if any. Under these provisions, we recorded a liability of $9 million and $10 million at September 30, 2016 and December 31, 2015, respectively, for profit in excess of the amount we are allowed to retain. Retroactive Premium Adjustments: The state Medicaid programs periodically adjust premium rates on a retroactive basis. In these cases, we must adjust our premium revenue in the period in which we learn of the adjustment, rather than in the months of service to which the retroactive adjustment applies. In the first quarter of 2016, our Florida health plan recorded a retroactive increase to Medicaid premium revenue of approximately $18 million relating to dates of service prior to 2016. Cost Plus Retroactive Premium Adjustments: In New Mexico, when members are retroactively enrolled into our health plan, we earn revenue only to the extent of the actual medical costs incurred by us for services provided during those retroactive periods, plus a small percentage of that medical cost for administration and profit. This arrangement first became effective July 1, 2014 (retroactive to January 1, 2014). We are paid normal monthly capitation rates for the retroactive eligibility periods, and the difference between those capitation rates and the amounts due to us on a cost plus basis are periodically settled with the state. To date, no such settlement has been made. During the years ended December 31, 2014 and 2015, our New Mexico contract was not specific as to the definition of retroactive membership, and the amount we owe the state (or that the state owes us) for the difference between capitation received and amounts due to us under the cost plus arrangement during those periods varies widely depending upon the definition of retroactive membership. Although we believe that the amount we have recorded as a liability for this matter is consistent with the state’s expectations, we cannot be certain that the state will not seek to recover an amount in excess of our recorded liability. Medicare Risk Adjustment: Our Medicare premiums are subject to retroactive increase or decrease based on the health status of our Medicare members (as measured by member risk score). We estimate our members' risk scores and the related amount of Medicare revenue that will ultimately be realized for the periods presented based on our knowledge of our members’ health status, risk scores and CMS practices. Based on our estimates, we have recorded a net payable of $17 million and $4 million for anticipated Medicare risk adjustment premiums and Medicare Part D settlements at September 30, 2016 and December 31, 2015, respectively. Marketplace Premium Stabilization Programs: The Affordable Care Act (ACA) established Marketplace premium stabilization programs effective January 1, 2014. These programs, commonly referred to as the "3R's," include a permanent risk adjustment program, a transitional reinsurance program, and a temporary risk corridor program. We record receivables or payables related to the 3R programs and the minimum annual medical loss ratio (Minimum MLR) when the amounts are reasonably estimable as described below, and, for receivables, collection is reasonably assured.
Income Taxes	Income Taxes The provision for income taxes is determined using an estimated annual effective tax rate, which is generally greater than the U.S. federal statutory rate primarily because of state taxes, nondeductible expenses such as the Health Insurer Fee (HIF), certain compensation, and other general and administrative expenses. The effective tax rate may be subject to fluctuations during the year, particularly as a result of the level of pretax earnings, and also as new information is obtained. Such information may affect the assumptions used to estimate the annual effective tax rate, including factors such as the mix of pretax earnings in the various tax jurisdictions in which we operate, valuation allowances against deferred tax assets, the recognition or the reversal of the recognition of tax benefits related to uncertain tax positions, and changes in or the interpretation of tax laws in jurisdictions where we conduct business. For example, in the third quarter of 2016 we entered into an agreement with the seller in the Pathways acquisition to change the allocation of the purchase price across certain legal entities, allowing us to recognize a $4 million tax benefit. We recognize deferred tax assets and liabilities for temporary differences between the financial reporting basis and the tax basis of our assets and liabilities, along with net operating loss and tax credit carryovers.
Recent Accounting Pronouncements	Recent Accounting Pronouncements Statement of Cash Flows. In August 2016, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2016-15, Classification of Certain Cash Receipts and Cash Payments, which amends Accounting Standards Codification (ASC) 230 to add or clarify guidance on eight classification issues related to the statement of cash flows such as debt prepayment or debt extinguishment costs, and contingent consideration payments made after a business combination. ASU 2016-15 is effective for fiscal periods beginning after December 15, 2017 and must be adopted using a retrospective transition method to each period presented but may be applied prospectively if retrospective application would be impracticable. Early adoption is permitted, including adoption in an interim period. We are evaluating the potential effects of the adoption to our financial statements. Revenue Recognition. In May 2016, the FASB issued ASU 2016-12, Revenue from Contracts with Customers (Topic 606). The amendments, which address transition, collectibility, non-cash consideration and the presentation of sales and other similar taxes, do not change the core principles of ASU 2014-09, but rather address implementation issues and are intended to result in more consistent application. We intend to adopt this standard on January 1, 2018. We are evaluating the potential effects of the adoption to our financial statements. In April 2016, the FASB issued ASU 2016-10, Identifying Performance Obligations and Licensing, which amends certain aspects of ASC 606, Revenue from Contracts with Customers. ASU 2016-10 amends step two of the new revenue standard’s five-step model to include guidance on immaterial promised goods or services, shipping and handling activities and identifying when promises represent performance obligations. ASU 2016-10 also provides guidance related to licensing such as, but not limited to, sales-based and usage-based royalties and renewals of licenses that provide a right to use intellectual property. We intend to adopt this standard on January 1, 2018. We are evaluating the potential effects of the adoption to our financial statements. In March 2016, the FASB issued ASU 2016-08, Revenue from Contracts with Customers - Principal vs. Agent Considerations, which amends the principal–versus–agent implementation guidance in ASC 606. ASU 2016-08 clarifies that an entity should evaluate whether it is the principal or agent for each specified good or service promised in a contract with a customer as defined in ASC 606. The entity must first identify each specified good or service to be provided to the customer and then assess whether it controls each specified good or service. The ASU also removed two of the five indicators used in evaluating control under the old guidance and reframes the remaining three indicators. We intend to adopt this standard on January 1, 2018. We are evaluating the potential effects of the adoption to our financial statements. Credit Losses. In June 2016, the FASB issued ASU 2016-13, Measurement of Credit Losses on Financial Instruments, which changes how companies measure credit losses on most financial instruments measured at amortized cost, such as loans, receivables and held-to-maturity debt securities. Rather than generally recognizing credit losses when it is probable that the loss has been incurred, the revised guidance requires companies to recognize an allowance for credit losses for the difference between the amortized cost basis of a financial instrument and the amount of amortized cost that the company expects to collect over the instrument's contractual life. ASU 2016-13 is effective for fiscal periods beginning after December 15, 2019 and must be adopted as a cumulative effect adjustment to retained earnings. Early adoption is permitted. We are evaluating the potential effects of the adoption to our financial statements. Stock Compensation. In March 2016, the FASB issued ASU 2016-09, Compensation-Stock Compensation, which simplifies several aspects of accounting for employee share-based payment transactions, including the accounting for income taxes, forfeitures, statutory tax and classification in the statement of cash flows. ASU 2016-09 is effective for fiscal periods beginning after December 15, 2016 and must be adopted using the modified retrospective approach except for classification in the statement of cash flows, which must be adopted using either the prospective or retrospective approach. Early adoption is permitted. We are evaluating the potential effects of the adoption to our financial statements. Other recent accounting pronouncements issued by the FASB (including its Emerging Issues Task Force), the American Institute of Certified Public Accountants, and the Securities and Exchange Commission (SEC) did not have, or are not believed by management to have, a material impact on our present or future consolidated financial statements.

Disclosure of accounting policy for income taxes, which may include its accounting policies for recognizing and measuring deferred tax assets and liabilities and related valuation allowances, recognizing investment tax credits, operating loss carryforwards, tax credit carryforwards, and other carryforwards, methodologies for determining its effective income tax rate and the characterization of interest and penalties in the financial statements.