| Fair Value Measurements By Level For Assets Measured At Fair Value On A Recurring Basis |
A summary of fair value measurements by level for assets and liabilities measured at fair value on a recurring basis at September 30, 2019 and December 31, 2018 is as follows: | | | | | | | | | | | | | | | | | | Level I | | Level II | | Level III | | Total | September 30, 2019 | | | | | | | | Assets: | | | | | | | | Cash equivalents | $ | 1,258 |
| | $ | — |
| | $ | — |
| | $ | 1,258 |
| Fixed maturity securities, available-for-sale: | | | | | | | | United States Government securities | — |
| | 497 |
| | — |
| | 497 |
| Government sponsored securities | — |
| | 131 |
| | — |
| | 131 |
| States, municipalities and political subdivisions | — |
| | 4,742 |
| | — |
| | 4,742 |
| Corporate securities | — |
| | 9,028 |
| | 311 |
| | 9,339 |
| Residential mortgage-backed securities | — |
| | 4,014 |
| | 3 |
| | 4,017 |
| Commercial mortgage-backed securities | — |
| | 90 |
| | — |
| | 90 |
| Other securities | — |
| | 1,651 |
| | 11 |
| | 1,662 |
| Total fixed maturity securities, available-for-sale | — |
| | 20,153 |
| | 325 |
| | 20,478 |
| Equity securities: |
|
| |
|
| |
|
| |
|
| Exchange traded funds | 563 |
| | — |
| | — |
| | 563 |
| Fixed maturity mutual funds | — |
| | 631 |
| | — |
| | 631 |
| Common equity securities | 796 |
| | 33 |
| | — |
| | 829 |
| Private equity securities | — |
| | — |
| | 306 |
| | 306 |
| Total equity securities | 1,359 |
| | 664 |
| | 306 |
| | 2,329 |
| Other invested assets, current | 10 |
| | — |
| | — |
| | 10 |
| Securities lending collateral | — |
| | 465 |
| | — |
| | 465 |
| Derivatives | — |
| | 25 |
| | — |
| | 25 |
| Total assets | $ | 2,627 |
| | $ | 21,307 |
| | $ | 631 |
| | $ | 24,565 |
| Liabilities: | | | | | | | | Derivatives | $ | — |
| | $ | (1 | ) | | $ | — |
| | $ | (1 | ) | Total liabilities | $ | — |
| | $ | (1 | ) | | $ | — |
| | $ | (1 | ) | | | | | | | | | December 31, 2018 | | | | | | | | Assets: | | | | | | | | Cash equivalents | $ | 1,815 |
| | $ | — |
| | $ | — |
| | $ | 1,815 |
| Fixed maturity securities, available-for-sale: | | | | | | | | United States Government securities | — |
| | 416 |
| | — |
| | 416 |
| Government sponsored securities | — |
| | 108 |
| | — |
| | 108 |
| States, municipalities and political subdivisions | — |
| | 4,785 |
| | — |
| | 4,785 |
| Corporate securities | 2 |
| | 7,648 |
| | 287 |
| | 7,937 |
| Residential mortgage-backed securities | — |
| | 2,744 |
| | 6 |
| | 2,750 |
| Commercial mortgage-backed securities | — |
| | 67 |
| | — |
| | 67 |
| Other securities | — |
| | 1,099 |
| | 17 |
| | 1,116 |
| Total fixed maturity securities, available-for-sale | 2 |
| | 16,867 |
| | 310 |
| | 17,179 |
| Equity securities: |
|
| |
|
| |
|
| |
|
| Exchange traded funds | 2 |
| | — |
| | — |
| | 2 |
| Fixed maturity mutual funds | — |
| | 557 |
| | — |
| | 557 |
| Common equity securities | 601 |
| | 53 |
| | — |
| | 654 |
| Private equity securities | — |
| | — |
| | 313 |
| | 313 |
| Total equity securities | 603 |
| | 610 |
| | 313 |
| | 1,526 |
| Other invested assets, current | 21 |
| | — |
| | — |
| | 21 |
| Securities lending collateral | 314 |
| | 290 |
| | — |
| | 604 |
| Derivatives | — |
| | 16 |
| | — |
| | 16 |
| Total assets | $ | 2,755 |
| | $ | 17,783 |
| | $ | 623 |
| | $ | 21,161 |
| Liabilities: | | | | | | | | Derivatives | $ | — |
| | $ | (17 | ) | | $ | — |
| | $ | (17 | ) | Total liabilities | $ | — |
| | $ | (17 | ) | | $ | — |
| | $ | (17 | ) |
|
| Reconciliation Of The Beginning And Ending Balances Of Assets Measured At Fair Value On A Recurring Basis Using Level III Inputs |
A reconciliation of the beginning and ending balances of assets measured at fair value on a recurring basis using Level III inputs for the three months ended September 30, 2019 and 2018 is as follows: | | | | | | | | | | | | | | | | | | | | | | Corporate Securities | | Residential Mortgage- backed Securities | | Other Securities | | Equity Securities | | Total | Three Months Ended September 30, 2019 | | | | | | | | | | Beginning balance at July 1, 2019 | $ | 297 |
| | $ | 3 |
| | $ | 11 |
| | $ | 305 |
| | $ | 616 |
| Total gains (losses): | | | | | | | | | | Recognized in net income | (3 | ) | | — |
| | — |
| | (5 | ) | | (8 | ) | Recognized in accumulated other comprehensive loss | 12 |
| | — |
| | — |
| | — |
| | 12 |
| Purchases | 28 |
| | — |
| | — |
| | 25 |
| | 53 |
| Sales | (9 | ) | | — |
| | — |
| | (19 | ) | | (28 | ) | Settlements | (18 | ) | | — |
| | — |
| | — |
| | (18 | ) | Transfers into Level III | 4 |
| | — |
| | — |
| | — |
| | 4 |
| Transfers out of Level III | — |
| | — |
| | — |
| | — |
| | — |
| Ending balance at September 30, 2019 | $ | 311 |
| | $ | 3 |
| | $ | 11 |
| | $ | 306 |
| | $ | 631 |
| Change in unrealized losses included in net income related to assets still held at September 30, 2019 | $ | — |
| | $ | — |
| | $ | — |
| | $ | (4 | ) | | $ | (4 | ) | | | | | | | | | | | Three Months Ended September 30, 2018 | | | | | | | | | | Beginning balance at July 1, 2018 | $ | 304 |
| | $ | 4 |
| | $ | 26 |
| | $ | 312 |
| | $ | 646 |
| Total gains (losses): | | | | | | | | | | Recognized in net income | — |
| | — |
| | — |
| | 4 |
| | 4 |
| Recognized in accumulated other comprehensive loss | (1 | ) | | — |
| | — |
| | — |
| | (1 | ) | Purchases | 32 |
| | — |
| | 3 |
| | 5 |
| | 40 |
| Sales | (2 | ) | | — |
| | — |
| | (3 | ) | | (5 | ) | Settlements | (30 | ) | | — |
| | — |
| | — |
| | (30 | ) | Transfers into Level III | 6 |
| | — |
| | 1 |
| | — |
| | 7 |
| Transfers out of Level III | (2 | ) | | — |
| | (13 | ) | | — |
| | (15 | ) | Ending balance at September 30, 2018 | $ | 307 |
| | $ | 4 |
| | $ | 17 |
| | $ | 318 |
| | $ | 646 |
| Change in unrealized gains included in net income related to assets still held at September 30, 2018 | $ | — |
| | $ | — |
| | $ | — |
| | $ | 9 |
| | $ | 9 |
|
A reconciliation of the beginning and ending balances of assets measured at fair value on a recurring basis using Level III inputs for the nine months ended September 30, 2019 and 2018 is as follows: | | | | | | | | | | | | | | | | | | | | | | Corporate Securities | | Residential Mortgage- backed Securities | | Other Securities | | Equity Securities | | Total | Nine Months Ended September 30, 2019 | | | | | | |
| | | Beginning balance at January 1, 2019 | $ | 287 |
| | $ | 6 |
| | $ | 17 |
| | $ | 313 |
| | $ | 623 |
| Total (losses) gains: | | | | | | | | | | Recognized in net income | (7 | ) | | — |
| | — |
| | (5 | ) | | (12 | ) | Recognized in accumulated other comprehensive loss | 14 |
| | — |
| | — |
| | — |
| | 14 |
| Purchases | 91 |
| | — |
| | 2 |
| | 46 |
| | 139 |
| Sales | (11 | ) | | — |
| | — |
| | (48 | ) | | (59 | ) | Settlements | (58 | ) | | (1 | ) | | (2 | ) | | — |
| | (61 | ) | Transfers into Level III | 4 |
| | — |
| | 3 |
| | — |
| | 7 |
| Transfers out of Level III | (9 | ) | | (2 | ) | | (9 | ) | | — |
| | (20 | ) | Ending balance at September 30, 2019 | $ | 311 |
| | $ | 3 |
| | $ | 11 |
| | $ | 306 |
| | $ | 631 |
| Change in unrealized losses included in net income related to assets still held at September 30, 2019 | $ | — |
| | $ | — |
| | $ | — |
| | $ | (4 | ) | | $ | (4 | ) | | | | | | | | | | | Nine Months Ended September 30, 2018 | | | | | | |
| | | Beginning balance at January 1, 2018 | $ | 229 |
| | $ | 5 |
| | $ | 16 |
| | $ | 287 |
| | $ | 537 |
| Total (losses) gains: | | | | | | | | | | Recognized in net income | 1 |
| | — |
| | — |
| | (228 | ) | | (227 | ) | Recognized in accumulated other comprehensive loss | (3 | ) | | — |
| | — |
| | — |
| | (3 | ) | Purchases | 94 |
| | — |
| | 12 |
| | 263 |
| | 369 |
| Sales | (17 | ) | | — |
| | — |
| | (4 | ) | | (21 | ) | Settlements | (60 | ) | | (1 | ) | | (1 | ) | | — |
| | (62 | ) | Transfers into Level III | 65 |
| | — |
| | 5 |
| | — |
| | 70 |
| Transfers out of Level III | (2 | ) | | — |
| | (15 | ) | | — |
| | (17 | ) | Ending balance at September 30, 2018 | $ | 307 |
| | $ | 4 |
| | $ | 17 |
| | $ | 318 |
| | $ | 646 |
| Change in unrealized gains included in net income related to assets still held at September 30, 2018 | $ | — |
| | $ | — |
| | $ | — |
| | $ | 27 |
| | $ | 27 |
|
|
| Carrying And Fair Values By Level Of Financial Instruments Not Recorded At Fair Value On Consolidated Balance Sheet |
A summary of the estimated fair values by level of each class of financial instrument that is recorded at its carrying value on our consolidated balance sheets at September 30, 2019 and December 31, 2018 is as follows: | | | | | | | | | | | | | | | | | | | | | | Carrying Value | | Estimated Fair Value | | | Level I | | Level II | | Level III | | Total | September 30, 2019 | | | | | | | | | | Assets: | | | | | | | | | | Other invested assets, long-term | $ | 3,914 |
| | $ | — |
| | $ | — |
| | $ | 3,914 |
| | $ | 3,914 |
| Liabilities: | | | | | | | | | | Debt: | | | | | | | | | | Short-term borrowings | 710 |
| | — |
| | 710 |
| | — |
| | 710 |
| Commercial paper | 500 |
| | — |
| | 500 |
| | — |
| | 500 |
| Notes | 18,841 |
| | — |
| | 20,198 |
| | — |
| | 20,198 |
| Convertible debentures | 179 |
| | — |
| | 893 |
| | — |
| | 893 |
| | | | | | | | | | | December 31, 2018 | | | | | | | | | | Assets: | | | | | | | | | | Other invested assets, long-term | $ | 3,726 |
| | $ | — |
| | $ | — |
| | $ | 3,726 |
| | $ | 3,726 |
| Liabilities: | | | | | | | | | | Debt: | | | | | | | | | | Short-term borrowings | 1,145 |
| | — |
| | 1,145 |
| | — |
| | 1,145 |
| Commercial paper | 697 |
| | — |
| | 697 |
| | — |
| | 697 |
| Notes | 17,178 |
| | — |
| | 17,145 |
| | — |
| | 17,145 |
| Convertible debentures | 191 |
| | — |
| | 1,030 |
| | — |
| | 1,030 |
|
|