Basis of Financial Statements (Policies)	3 Months Ended	12 Months Ended
Basis of Financial Statements (Policies)	Mar. 31, 2018	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Financial Statements	The unaudited financial information in this report includes the accounts of Fidelity National Financial, Inc. and its subsidiaries (collectively, “we,” “us,” “our,” or “FNF”) prepared in accordance with U.S. generally accepted accounting principles ("GAAP") and the instructions to Form 10-Q and Article 10 of Regulation S-X. All adjustments considered necessary for a fair presentation have been included. All adjustments made were of a normal, recurring nature.
Earnings Per Share	Earnings Per Share Basic earnings per share, as presented on the Condensed Consolidated Statement of Earnings, is computed by dividing net earnings available to common shareholders in a given period by the weighted average number of common shares outstanding during such period. In periods when earnings are positive, diluted earnings per share is calculated by dividing net earnings available to common shareholders by the weighted average number of common shares outstanding plus the impact of assumed conversions of potentially dilutive securities. For periods when we recognize a net loss, diluted earnings per share is equal to basic earnings per share as the impact of assumed conversions of potentially dilutive securities is considered to be antidilutive. We have granted certain stock options, shares of restricted stock, convertible debt instruments and certain other convertible share based payments which have been treated as common share equivalents for purposes of calculating diluted earnings per share for periods in which positive earnings have been reported. Options or other instruments which provide the ability to purchase shares of our common stock that are antidilutive are excluded from the computation of diluted earnings per share.	Basic earnings per share, as presented on the Consolidated Statement of Earnings, is computed by dividing net earnings available to common shareholders by the weighted average number of common shares outstanding during the period. In periods when earnings are positive, diluted earnings per share is calculated by dividing net earnings available to common shareholders by the weighted average number of common shares outstanding plus the impact of assumed conversions of potentially dilutive securities. For periods when we recognize a net loss, diluted earnings per share is equal to basic earnings per share as the impact of assumed conversions of potentially dilutive securities is considered to be antidilutive. We have granted certain stock options, shares of restricted stock, convertible debt instruments and certain other convertible share based payments which have been treated as common share equivalents for purposes of calculating diluted earnings per share for periods in which positive earnings have been reported. Options or other instruments which provide the ability to purchase shares of our common stock that are antidilutive are excluded from the computation of diluted earnings per share.
Recent Accounting Pronouncements	Recent Accounting Pronouncements Revenue Recognition In May 2014, the Financial Accounting Standards Board ("FASB") issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606). This ASU provides a new comprehensive revenue recognition model that requires companies to recognize revenue to depict the transfer of goods or services to a customer at an amount that reflects the consideration it expects to receive in exchange for those goods or services. This update also requires additional disclosure about the nature, amount, timing and uncertainty of revenue and cash flows arising from customer contracts. This update permits the use of either the retrospective or cumulative effect transition method. ASU No. 2016-08, Revenue from Contracts with Customers (Topic 606): Principal versus Agent Considerations was issued by FASB in March 2016 to clarify the principal versus agent considerations within ASU 2014-09. ASU 2016-10 Revenue from Contracts with Customers (Topic 606): Identifying Performance Obligations and Licensing was issued by the FASB in April 2016 to clarify how to determine whether goods and services are separately identifiable and thus accounted for as separate performance obligations. ASU 2016-12 Revenue from Contracts with Customers (Topic 606): Narrow-Scope Improvements and Practical Expedients was issued by the FASB in May 2016 to clarify certain terms from the aforementioned updates and to add practical expedients for contracts at various stages of completion. ASU 2016-20, Technical Corrections and Improvements to Topic 606, Revenue from Contracts with Customers, was issued by the FASB in December 2016 which includes thirteen technical corrections and improvements affecting narrow aspects of the guidance issued in ASU 2014-09. We adopted these revenue standards on January 1, 2018 using the modified retrospective approach. As there was no impact to our historical revenue recognition, we did not record a cumulative-effect adjustment to the opening balance of retained earnings in the current year. See Note J. Revenue Recognition for further discussion of our revenue. Other Adopted Pronouncements In January 2016, the FASB issued ASU No. 2016-01 Financial Instruments - Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities. The primary amendments required by the ASU include: requiring equity investments with readily determinable fair values to be measured at fair value through net income rather than through other comprehensive income; allowing entities with equity investments without readily determinable fair values to report the investments at cost, adjusted for changes in observable prices, less impairment; requiring entities that elect the fair value option for financial liabilities to report the change in fair value attributable to instrument-specific credit risk in other comprehensive income; and clarifying that entities should assess the need for a valuation allowance on a deferred tax asset related to available-for-sale debt securities in combination with other deferred tax assets. The amendments in this ASU are effective for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. The ASU requires a cumulative-effect adjustment of the balance sheet as of the beginning of the year of adoption. Early adoption of the ASU is not permitted, except for the provision related to financial liabilities for which the fair value option has been elected. We adopted this new guidance on January 1, 2018, which resulted in the reclassification of our unrealized gains and losses on our equity and preferred securities available for sale previously included in accumulated other comprehensive income to beginning retained earnings. Changes in the fair value of our investments in equity and preferred securities subsequent to January 1, 2018 are now included in our earnings from continuing operations. We reclassified a total of $109 million from Accumulated other comprehensive income to beginning Retained earnings as of January 1, 2018. The total cumulative effect on opening equity, including an increase in Retained earnings of $19 million attributable to an increase in value of certain Other long term investments resulting from recording at fair value, was an increase in Retained earnings of $128 million and decrease in Accumulated other comprehensive income of $109 million. In November 2016, the FASB issued ASU No. 2016-18 Statement of Cash Flows (Topic 230): Restricted Cash. The amendments in this ASU require that a statement of cash flows explain the change during the period in the total of cash, cash equivalents, and amounts generally described as restricted cash or restricted cash equivalents. GAAP currently does not include specific guidance on the cash flow classification and presentation of changes in restricted cash. The Company previously excluded cash pledged related to secured trust deposits, which generally meets the definition of restricted cash, from the reconciliation of beginning-of-period to end-of-period total amounts shown on the statement of cash flows. This update is effective for annual periods beginning after December 15, 2017, including interim periods within those fiscal years. The ASU requires retrospective application to all prior periods presented upon adoption. We adopted this ASU on January 1, 2018. The adoption of this ASU resulted in the following retrospective changes to our Statement of Cash Flows for the three months ended March 31, 2017: an increase in the net change in cash and cash equivalents of $67 million due to the inclusion of the change in our cash pledged against secured trust deposits, an increase in investing cash inflow of $179 million related to the movement of cash paid for investments pledged against secured trust deposits from operating to investing activities, and an increase in financing cash outflow of $112 million related to the movement of the change in secured trust deposits from operating to financing activities. Other Pronouncements Not Yet Adopted In February 2016, the FASB issued ASU No. 2016-02 Leases (Topic 842). The amendments in this ASU introduce broad changes to the accounting and reporting for leases by lessees. The main provisions of the new standard include: clarifications to the definitions of a lease, components of leases, and criteria for determining lease classification; requiring virtually all leased assets, including operating leases and related liabilities resulting from applying the fair value measurement, to be reflected on the lessee's balance sheet; and expanding and adding to the required disclosures for lessees. This update is effective for annual and interim periods beginning after December 15, 2018, including interim periods within those fiscal years. Early application of the standard is permitted. The ASU requires a modified retrospective approach to transitioning which allows for the use of practical expedients to effectively account for leases commenced prior to the effective date in accordance with previous GAAP, except that lessees are required to recognize a right-of-use asset and a lease liability for all operating leases at each reporting date based on the present value of the remaining minimum rental payments that were tracked and disclosed under previous GAAP. We are still evaluating the totality of the effects this new guidance will have on our business process and systems, consolidated financial statements, and related disclosures. We have identified a vendor with software suited to track and account for leases under the new standard. We have not concluded on the anticipated financial statement effects of adoption. We plan to adopt this standard on January 1, 2019. In June 2016, the FASB issued ASU No. 2016-13 Financial Instruments - Credit Losses: Measurement of Credit Losses on Financial Instruments. The amendments in this ASU introduce broad changes to accounting for credit impairment of financial instruments. The primary updates include the introduction of a new current expected credit loss ("CECL") model that is based on expected rather than incurred losses and amendments to the accounting for impairment of fixed maturity securities available for sale. This update is effective for annual periods beginning after December 15, 2019, including interim periods within those fiscal years. Early adoption is permitted for annual periods beginning after December 15, 2018, including interim periods within those fiscal years. We are currently evaluating the effect this new guidance will have on our consolidated financial statements and related disclosures and have not yet concluded on its effects. We do not plan to early adopt the standard. In January 2017, the FASB issued ASU 2017-04, Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment. The guidance simplifies the measurement of goodwill impairment by removing step 2 of the goodwill impairment test, which requires the determination of the fair value of individual assets and liabilities of a reporting unit. The new guidance requires goodwill impairment to be measured as the amount by which a reporting unit’s carrying value exceeds its fair value; however, the loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. The amendments should be applied on a prospective basis. The new standard is effective for fiscal years beginning after December 15, 2019 with early adoption permitted for interim or annual goodwill impairment tests performed after January 1, 2017. We are currently evaluating the effect this new guidance will have on our consolidated financial statements and related disclosures and have not yet concluded on its effects. On January 1, 2018, we adopted ASC Topic 606 by applying the modified retrospective method. Results for reporting periods beginning after January 1, 2018 are presented under Topic 606, while prior period amounts are not adjusted and continue to be reported under the accounting standards in effect for the prior period. The adoption of ASC Topic 606 did not have an impact on the recognition of our primary sources of revenue, direct and agency title premiums, as those revenue streams are subject to the accounting and reporting requirements under ASC Topic 944. Timing of recognition of substantially all of our remaining revenue was also not impacted and we therefore did not record any cumulative effect adjustment to opening equity.	Recent Accounting Pronouncements Revenue Recognition In May 2014, the Financial Accounting Standards Board ("FASB") issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606). This ASU provides a new comprehensive revenue recognition model that requires companies to recognize revenue to depict the transfer of goods or services to a customer at an amount that reflects the consideration it expects to receive in exchange for those goods or services. This update also requires additional disclosure about the nature, amount, timing and uncertainty of revenue and cash flows arising from customer contracts. This update permits the use of either the retrospective or cumulative effect transition method. ASU No. 2016-08, Revenue from Contracts with Customers (Topic 606): Principal versus Agent Considerations was issued by FASB in March 2016 to clarify the principal versus agent considerations within ASU 2014-09. ASU 2016-10 Revenue from Contracts with Customers (Topic 606): Identifying Performance Obligations and Licensing was issued by the FASB in April 2016 to clarify how to determine whether goods and services are separately identifiable and thus accounted for as separate performance obligations. ASU 2016-12 Revenue from Contracts with Customers (Topic 606): Narrow-Scope Improvements and Practical Expedients was issued by the FASB in May 2016 to clarify certain terms from the aforementioned updates and to add practical expedients for contracts at various stages of completion. ASU 2016-20, Technical Corrections and Improvements to Topic 606, Revenue from Contracts with Customers, was issued by the FASB in December 2016 which includes thirteen technical corrections and improvements affecting narrow aspects of the guidance issued in ASU 2014-09. We have completed our analysis of the impact of the standards and have concluded that these standards will not have a material impact on our accounting or reporting. Upon issuance of ASU 2015-14, the effective date of ASU 2014-09 was deferred to annual and interim periods beginning on or after December 15, 2017. We will adopt the guidance on January 1, 2018. Either of the following transition methods is permitted: (i) a full retrospective approach reflecting the application of the new standard in each prior reporting period, or (ii) a modified retrospective approach with a cumulative-effect adjustment to the opening balance of retained earnings in the year the new standard is first applied. We plan to transition to this new guidance using the modified retrospective approach. Other Pronouncements In January 2016, the FASB issued ASU No. 2016-01 Financial Instruments - Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities. The primary amendments required by the ASU include: requiring equity investments with readily determinable fair values to be measured at fair value through net income rather than through other comprehensive income; allowing entities with equity investments without readily determinable fair values to report the investments at cost, adjusted for changes in observable prices, less impairment; requiring entities that elect the fair value option for financial liabilities to report the change in fair value attributable to instrument-specific credit risk in other comprehensive income; and clarifying that entities should assess the need for a valuation allowance on a deferred tax asset related to available-for-sale debt securities in combination with other deferred tax assets. The amendments in this ASU are effective for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. The ASU requires a cumulative-effect adjustment of the balance sheet as of the beginning of the year of adoption. Early adoption of the ASU is not permitted, except for the provision related to financial liabilities for which the fair value option has been elected. We have completed our evaluation of the effects this new guidance will have on our consolidated financial statements and related disclosures and have determined that the ASU will result in: (1) reclassification of our unrealized gains and losses on our equity and preferred securities available for sale currently included in accumulated other comprehensive income to beginning retained earnings as of January 1, 2018 and (2) changes in fair value of our equity and preferred securities available for sale subsequent to January 1, 2018 to be included in our earnings from continuing operations. As of December 31, 2017, we held equity and preferred securities available for sale with combined net unrealized gains (net of losses) of $164 million and $12 million, respectively. Including the associated effects of deferred taxes, based on the net of tax balances as of December 31, 2017, we expect to reclassify a total of approximately $109 million from Accumulated other comprehensive income to beginning Retained earnings as of January 1, 2018. In February 2016, the FASB issued ASU No. 2016-02 Leases (Topic 842). The amendments in this ASU introduce broad changes to the accounting and reporting for leases by lessees. The main provisions of the new standard include: clarifications to the definitions of a lease, components of leases, and criteria for determining lease classification; requiring virtually all leased assets, including operating leases and related liabilities, to be reflected on the lessee's balance sheet; and expanding and adding to the required disclosures for lessees. This update is effective for annual and interim periods beginning after December 15, 2018, including interim periods within those fiscal years. Early application of the standard is permitted. The ASU requires a modified retrospective approach to transitioning which allows for the use of practical expedients to effectively account for leases commenced prior to the effective date in accordance with previous GAAP, except that lessees are required to recognize a right-of-use asset and a lease liability for all operating leases at each reporting date based on the present value of the remaining minimum rental payments that were tracked and disclosed under previous GAAP. We are still evaluating the totality of the effects this new guidance will have on our business process and systems, consolidated financial statements, related disclosures. We have identified a vendor with software suited to track and account for leases under the new standard. We have not concluded on the anticipated financial statement effects of adoption. We plan to adopt this standard on January 1, 2019. We are currently evaluating the impact of the adoption of this standard on our consolidated financial statements. In June 2016, the FASB issued ASU No. 2016-13 Financial Instruments - Credit Losses: Measurement of Credit Losses on Financial Instruments. The amendments in this ASU introduce broad changes to accounting for credit impairment of financial instruments. The primary updates include the introduction of a new current expected credit loss ("CECL") model that is based on expected rather than incurred losses and amendments to the accounting for impairment of debt securities available for sale. This update is effective for annual periods beginning after December 15, 2019, including interim periods within those fiscal years. Early adoption is permitted for annual periods beginning after December 15, 2018, including interim periods within those fiscal years. We are currently evaluating the effect this new guidance will have on our consolidated financial statements and related disclosures and have not yet concluded on its effects. We do not plan to early adopt the standard. In August 2016, the FASB issued ASU No. 2016-15 Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments. The amendments in this ASU introduce clarifications to the presentation of certain cash receipts and cash payments in the statement of cash flows. The primary updates include additions and clarifications of the classification of cash flows related to certain debt repayment activities, contingent consideration payments related to business combinations, proceeds from insurance policies, distributions from equity method investees, and cash flows related to securitized receivables. This update is effective for annual periods beginning after December 15, 2017, including interim periods within those fiscal years. Early adoption of this ASU is permitted, including in interim periods. The ASU requires retrospective application to all prior periods presented upon adoption. We will adopt this ASU on January 1, 2018 and based on our preliminary analysis, we do not expect the adoption of this ASU to have a material impact on our resulting operating, investing, or financing cash flows. In November 2016, the FASB issued ASU No. 2016-18 Statement of Cash Flows (Topic 230): Restricted Cash. The amendments in this ASU require that a statement of cash flows explain the change during the period in the total of cash, cash equivalents, and amounts generally described as restricted cash or restricted cash equivalents. GAAP currently does not include specific guidance on the cash flow classification and presentation of changes in restricted cash. The Company currently excludes cash pledged related to secured trust deposits, which generally meets the definition of restricted cash, from the reconciliation of beginning-of-period to end-of-period total amounts shown on the statement of cash flows. This update is effective for annual periods beginning after December 15, 2017, including interim periods within those fiscal years. Early adoption of this ASU is permitted, including in interim periods. The ASU requires retrospective application to all prior periods presented upon adoption. We will adopt this ASU on January 1, 2018. Based on our preliminary analysis, we expect the adoption of this ASU to result in the movement of the change in our cash pledged against secured trust deposits from operating activities to the net change in cash, the change in investments pledged against secured trust deposits from operating to investing activities, and the change in secured trust deposits from operating to financing activities. In January 2017, the FASB issued ASU 2017-01, Business Combinations (Topic 805): Clarifying the Definition of a Business to assist companies with evaluating whether transactions should be accounted for as acquisitions of assets or businesses. The new guidance requires a company to evaluate if substantially all of the fair value of the gross assets acquired (or disposed of) is concentrated in a single identifiable asset or a group of similar identifiable assets; if so, the set of assets and activities is not a business. The guidance also requires a business to include at least one substantive process and narrows the definition of outputs by more closely aligning it with how outputs are described in the guidance for revenue from contracts with customers. The new standard is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2017, with early adoption permitted. The guidance should be applied prospectively to any transactions occurring within the period of adoption. We will adopt this ASU on January 1, 2018. Based on our historical acquisition activity, we do not expect this to have a material impact on our ongoing accounting or financial reporting. In January 2017, the FASB issued ASU 2017-04, Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment. The guidance simplifies the measurement of goodwill impairment by removing step 2 of the goodwill impairment test, which requires the determination of the fair value of individual assets and liabilities of a reporting unit. The new guidance requires goodwill impairment to be measured as the amount by which a reporting unit’s carrying value exceeds its fair value; however, the loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. The amendments should be applied on a prospective basis. The new standard is effective for fiscal years beginning after December 15, 2019 with early adoption permitted for interim or annual goodwill impairment tests performed after January 1, 2017. We are currently evaluating the effect this new guidance will have on our consolidated financial statements and related disclosures and have not yet concluded on its effects. In March 2017, the FASB issued ASU No. 2017-08, Receivables-Nonrefundable Fees and Other Costs (Topic 310-20): Premium Amortization on Purchased Callable Debt Securities. The amendments in this ASU shortens the amortization period for the premium on certain purchased callable debt securities to the earliest call date. The new guidance does not change the accounting for purchased callable debt securities held at a discount. This update is effective for annual periods beginning after December 15, 2018, including interim periods within those fiscal years. Early adoption of this ASU is permitted, including in interim periods. We early adopted the standard as of January 1, 2017. The adoption of this standard did not have a material impact on our financial statements.
Insurance Premiums Revenue Recognition	Our Direct title insurance premiums are recognized as revenue at the time of closing of the underlying transaction as the earnings process is then considered complete. Regulation of title insurance rates varies by state. Premiums are charged to customers based on rates predetermined in coordination with each states' respective Department of Insurance. Cash associated with such revenue is typically collected at closing of the underlying real estate transaction. Premium revenues from agency title operations are recognized when the underlying title order and transaction closing, if applicable, are complete and the agent has been invoiced. Revenues from our home warranty business are generated from contracts with customers to provide warranty for major home appliances. Contracts are one year in length and revenue is recognized ratably over the term of the contract.
Revenue Recognition, Services, Real Estate Transactions	Escrow fees and Other title-related fees and income in our Title segment are closely related to Direct title insurance premiums and are primarily associated with managing the closing of real estate transactions including the processing of funds on behalf of the transaction participants, gathering and recording the required closing documents, providing notary and home inspection services, and other real estate or title related activities. Revenue is primarily recognized upon closing of the underlying real estate transaction or completion of services. Cash associated with such revenue is typically collected at closing. Revenues from our ServiceLink subsidiary, excluding its title premiums, escrow fees, and loan subservicing fees primarily include revenues from real estate appraisal services and foreclosure processing and facilitation services. Revenues from real estate appraisal services are recognized when all appraisal work is complete, a final report is issued to the client and the client is billed. Revenues from foreclosure processing and facilitation services are primarily recognized upon completion of the services and when billing to the client is complete. Real estate brokerage revenues are primarily comprised of commission revenues earned in association with the facilitation of real estate transactions and are recognized upon closing of the sale of the underlying real estate transaction. Real estate technology revenues are primarily comprised of subscription fees for use of software provided to real estate professionals. Subscriptions are only offered on a month-by-month basis and fees are billed monthly. Revenue is recognized in the month services are provided. Loan subservicing revenues are generated by certain subsidiaries of ServiceLink and are associated with the servicing of mortgage loans on behalf of its customers. Revenue is recognized when the underlying work is performed and billed. Loan subservicing revenues are subject to the recognition requirements of ASC Topic 860.
Revenue Recognition, Other	Interest and investment income consists primarily of interest payments received on fixed maturity security holdings and dividends received on equity and preferred security holdings. We do not disclose the value of unsatisfied performance obligations for (i) contracts with an original expected length of one year or less, primarily related to revenue from our home warranty business, and (ii) contracts for which we recognize revenue at the amount to which we have the right to invoice for services performed.