We are a leading provider of (i) title insurance, escrow and other title-related services, including trust activities, trustee sales guarantees, recordings and reconveyances and home warranty products and (ii) technology and transaction services to the real estate and mortgage industries. FNF is one of the nation’s largest title insurance companies operating through its title insurance underwriters - Fidelity National Title Insurance Company ("FNTIC"), Chicago Title Insurance Company ("Chicago Title"), Commonwealth Land Title Insurance Company ("Commonwealth Title"), Alamo Title Insurance and National Title Insurance of New York Inc. - which collectively issue more title insurance policies than any other title company in the United States. Through our subsidiary, ServiceLink Holdings, LLC ("ServiceLink"), we provide mortgage transaction services, including title-related services and facilitation of production and management of mortgage loans.
We have other intangible assets, not including goodwill, which consist primarily of customer relationships and contracts, trademarks and tradenames, and computer software, which are generally recorded in connection with acquisitions at their fair value. Intangible assets with estimable lives are amortized over their respective estimated useful lives to their estimated residual values and reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount may not be recoverable. In general, customer relationships are amortized over their estimated useful lives, generally ten years, using an accelerated method which takes into consideration expected customer attrition rates. Contractual relationships are generally amortized over their contractual life. Trademarks and tradenames are generally amortized over ten years. Capitalized software includes the fair value of software acquired in business combinations, purchased software and capitalized software development
The cost basis and fair values of our available for sale securities at December 31, 2019 and 2018 are as follows:
In conjunction with the FNFV Split-Off, FNTIC, Chicago Title, and Commonwealth Title contributed an aggregate of $100 million to Cannae in exchange for 5,706,134 shares of Cannae common stock. As of December 31, 2019, we own approximately 7.2% of Cannae's outstanding common equity. In addition, we issued to Cannae a revolver note (the "Cannae Revolver") in the aggregate principal amount of up to $100 million, which accrues interest at LIBOR plus 450 basis points and matures on the five-year anniversary of the date of the revolver note. The maturity date is automatically extended for additional five-year terms unless notice of non-renewal is otherwise provided by either FNF or Cannae, in their sole discretion.
A reconciliation of the net earnings of Black Knight and FNFV to the Statement of Operations is shown below:
Amortization expense for amortizable intangible assets, which consist primarily of customer relationships and computer software, was $131 million, $119 million, and $130 million for the years ended December 31, 2019, 2018 and 2017, respectively. Estimated amortization expense for the next five years for assets owned at December 31, 2019, is $115 million in 2020, $87 million in 2021, $65 million in 2022, $46 million in 2023 and $20 million in 2024.
At this time, the Company is unable to ascertain its liability, if any, and is unable to make an estimate of a reasonably possible claim loss for any of these claims due to the complex nature of the claims and litigation, the early procedural status of each claim (involving unresolved questions of fact without any rulings on the merits or determinations of liability), the extent of discovery not yet conducted, potential insurance coverage, and an incomplete evaluation of possible defenses, counterclaims, crossclaims or third-party claims that may exist. Moreover, it is likely that in some instances, the claims listed above are duplicative. The Company, however, has recorded an incurred claim loss reserve for legal fees related to these matters as of December 31, 2019, which is included in its consolidated reserve for claim losses. As further information becomes available, the Company will continue to evaluate the adequacy of its consolidated reserve for claim losses.
We account for stock-based compensation plans in accordance with GAAP on share-based payments, which requires that compensation cost relating to share-based payments be recognized in the consolidated financial statements based on the fair value of each award. Using the fair value method of accounting, compensation cost is measured based on the fair value of the award at the grant date and recognized over the service period. Fair value of restricted stock awards and units is based on the grant date value of the underlying stock derived from quoted market prices. The total fair value of restricted stock awards granted in the years ended December 31, 2019, 2018 and 2017 was $29 million, $29 million, and $31 million, respectively. The total fair value of restricted stock awards which vested in the years ended December 31, 2019, 2018 and 2017 was $42 million, $29 million, and $38 million, respectively. Option awards are measured at fair value on the grant date using the Black Scholes Option Pricing Model. The intrinsic value of options exercised in the years ended December 31, 2019, 2018 and 2017 was $48 million, $19 million, and $25 million, respectively. Net earnings attributable to FNF Shareholders reflects stock-based compensation expense amounts of $38 million for the year ended December 31, 2019, $31 million for the year ended December 31, 2018, and $44 million for the year ended December 31, 2017, which are included in personnel costs in the reported financial results of each period.
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 previously did 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.