| In millions, except per share items | Jun-30-23 | Dec-31-22 | Jun-30-22 | Mar-31-22 | Dec-31-21 | Sep-30-21 | Jun-30-21 | Mar-31-21 |
| | 10-Q | 8-K | 10-Q | 10-Q | 10-K | 10-Q | 10-Q | 10-Q |
| Cash Flows From Operating Activities | | | | | | | | |
| Net Income (Loss) | 534.0 | | -811.0 | -273.0 | 1,470.0 | 153.0 | 703.0 | 620.0 |
| |
| Adjustments to reconcile net income to net cash from operating activities: | | | | | | | | |
| Depreciation, amortization and other | | | 49.0 | 29.0 | 49.0 | 23.0 | 23.0 | 23.0 |
| Investment gains and losses, net | | | 1,155.0 | 674.0 | -1,420.0 | 78.0 | -510.0 | -501.0 |
| Interest credited to contract holders | | | 11.0 | 12.0 | 12.0 | 10.0 | 12.0 | 11.0 |
| Deferred income tax expense | 81.0 | | 4.0 | -85.0 | 26.0 | -40.0 | 23.0 | -34.0 |
| Changes in: | | | | | | | | |
| Premiums and reinsurance receivable | | | -245.0 | -182.0 | 40.0 | 85.0 | -199.0 | -166.0 |
| Deferred policy acquisition costs | | | -62.0 | -68.0 | 11.0 | 10.0 | -45.0 | -49.0 |
| Other assets | | | -9.0 | -20.0 | 1.0 | 11.0 | 10.0 | -33.0 |
| Loss and loss expense reserves | | | 303.0 | 61.0 | 13.0 | 273.0 | 69.0 | 204.0 |
| Life policy and investment contract reserves | | | 21.0 | 17.0 | 23.0 | 21.0 | 40.0 | 15.0 |
| Unearned premiums | | | 307.0 | 289.0 | -71.0 | -75.0 | 236.0 | 221.0 |
| Other liabilities | | | 105.0 | -136.0 | 33.0 | 72.0 | 103.0 | -80.0 |
| Current income tax receivable/payable | 81.0 | | 4.0 | -85.0 | 26.0 | -40.0 | 23.0 | -34.0 |
| Net cash provided by operating activities | 615.0 | | 557.0 | 198.0 | 463.0 | 601.0 | 563.0 | 354.0 |
| |
| Cash Flows From Investing Activities | | | | | | | | |
| Sale, call or maturity of fixed maturities | | | 647.0 | 55.0 | 1,373.0 | 15.0 | 43.0 | 30.0 |
| Sale of equity securities | | | 122.0 | 56.0 | 13.0 | 123.0 | 45.0 | 65.0 |
| Purchase of fixed maturities | | | -482.0 | -460.0 | -557.0 | -603.0 | -761.0 | -467.0 |
| Purchase of equity securities | | | -128.0 | -90.0 | -37.0 | -276.0 | -74.0 | -78.0 |
| Changes in finance receivables | | | 11.0 | | | | | |
| Investment in building and equipment | | | -4.0 | -4.0 | -3.0 | -3.0 | -4.0 | -5.0 |
| Change in other invested assets, net | | | -26.0 | -21.0 | 94.0 | -24.0 | -12.0 | 6.0 |
| Net cash used in investing activities | | | -162.0 | -162.0 | -166.0 | -365.0 | -373.0 | -153.0 |
| |
| Cash Flows From Financing Activities | | | | | | | | |
| Shares acquired - share repurchase authorization | | | -151.0 | -45.0 | -104.0 | -12.0 | | -28.0 |
| Changes in note payable | | | -5.0 | -5.0 | | | 2.0 | 3.0 |
| Proceeds from stock options exercised | | | 2.0 | 4.0 | 3.0 | 2.0 | 4.0 | 4.0 |
| Contract holders' funds deposited | | | 16.0 | 18.0 | 21.0 | 17.0 | 20.0 | 27.0 |
| Contract holders' funds withdrawn | | | -30.0 | -32.0 | -42.0 | -29.0 | -42.0 | -33.0 |
| Other | | | -7.0 | -29.0 | -16.0 | -32.0 | -18.0 | -32.0 |
| Net cash used in financing activities | | | -284.0 | -188.0 | -243.0 | -154.0 | -134.0 | -154.0 |
| Net change in cash and cash equivalents | | | 111.0 | -152.0 | 54.0 | 82.0 | 56.0 | 47.0 |
| |
| Supplemental Disclosures of Cash Flow Information: | | | | | | | | |
| Interest paid | | | 26.0 | | 26.0 | | 26.0 | |
| Noncash Activities | | | | | | | | |
| Equipment acquired under finance lease obligations | | | 4.0 | 2.0 | 3.0 | 1.0 | 5.0 | 3.0 |
| Share-based compensation | | | -3.0 | 27.0 | -21.0 | 9.0 | 13.0 | 25.0 |
| Other assets and other liabilities | | | 170.0 | 10.0 | -50.0 | 54.0 | 39.0 | 44.0 |