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Income Taxes (Tables) | 12 Months Ended
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Dec. 31, 2017
Income Tax Disclosure [Abstract] |
Net deferred tax assets and liabilities | Net deferred tax assets and liabilities as of December 31, 2017 and 2016 are as follows:
| Table | 12.1 |  |  |  |
Deferred tax assets and liabilities | (in thousands) |  | 2017 |  | 2016
Total deferred tax assets |  | $ | 258,663 |  |  | $ | 636,449 |
Total deferred tax liabilities |  | (24,282 | ) |  | (28,794 | )
| Net deferred tax asset |  | $ | 234,381 |  |  | $ | 607,655 |
Components of the net deferred tax asset (liability) | Table 12.2 includes the components of the net deferred tax asset as of December 31, 2017 and 2016.
| Table | 12.2 |  |  |  |
Deferred tax components | (in thousands) |  | 2017 |  | 2016
Unearned premium reserves |  | $ | 29,196 |  |  | $ | 40,153 |
| Benefit plans |  | (7,162 | ) |  | (12,350 | )
| Federal net operating loss |  | 155,839 |  |  | 520,812 |
| Loss reserves |  | 4,994 |  |  | 10,883 |
| Unrealized (appreciation) depreciation in investments |  | (7,782 | ) |  | 11,211 |
| Mortgage investments |  | 8,963 |  |  | 17,751 |
| Deferred compensation |  | 7,265 |  |  | 12,517 |
| AMT credit carryforward |  | 37,017 |  |  | 2,215 |
| Other, net |  | 6,051 |  |  | 4,463 |
| Net deferred tax asset |  | $ | 234,381 |  |  | $ | 607,655 |
Summary of valuation allowance | Table 12.3 provides a rollforward of our deferred tax asset valuation allowance for the year ended December 31, 2015.
| Table | 12.3 |  |
Deferred tax valuation allowance rollforward | (in millions) |  | For the year ended December 31, 2015
Balance at December 31, 2014 |  | $ | 902.3 |
| Reduction in tax provision in current year |  | (161.1 | )
| Amounts recorded in other comprehensive income in the current year |  | 6.3 |
| Change in valuation allowance for deferred tax assets in the current year |  | (154.8 | )
| Reduction in tax provision for amounts to be realized in future years |  | (686.7 | )
| Amounts recorded in other comprehensive income to be realized in future years |  | (60.8 | )
| Change in valuation allowance for deferred tax assets realizable in future years |  | (747.5 | )
| Balance at December 31, 2015 |  | $ | — |
Tax provision (benefit) | Table 12.4 shows the effect of the change in valuation allowance on the provision for (benefit from) income taxes for the year ended December 31, 2015.
| Table | 12.4 |  |
Provision for (benefit from) income taxes | (in thousands) |  | 2015
Provision for income taxes before valuation allowance |  | $ | 163,497 |
Change in valuation allowance |  | (161,158 | )
| Reversal of valuation allowance |  | (686,652 | )
| Benefit from income taxes |  | $ | (684,313 | )
Components of the provision for (benefit from) income taxes | Table 12.5 summarizes the components of the provision for (benefit from) income taxes:
| Table | 12.5 |  |  |  |  |  |
Provision for (benefit from) income taxes | (in thousands) |  | 2017 |  | 2016 |  | 2015
Current Federal |  | $ | 73,348 |  |  | $ | 9,470 |  |  | $ | 8,067 |
Deferred Federal |  | 351,677 |  |  | 160,657 |  |  | (686,652 | )
| Other |  | 3,710 |  |  | 2,070 |  |  | (5,728 | )
| Provision for (benefit from) income taxes |  | $ | 428,735 |  |  | $ | 172,197 |  |  | $ | (684,313 | )
Reconciliation of federal statutory income tax rate | Table 12.6 reconciles the federal statutory income tax rate to our effective tax provision (benefit) rate.
| Table | 12.6 |  |  |  |  |
Effective tax rate reconciliation |  | 2017 |  | 2016 |  | 2015
Federal statutory income tax rate | 35.0 | % |  | 35.0 | % |  | 35.0 | %
| Additional income tax provision related to the rate decrease included in the Tax Act | 17.0 | % |  | — | % |  | — | %
| Additional income tax provision related to IRS litigation | 3.7 | % |  | 0.1 | % |  | 0.1 | %
| Valuation allowance | — | % |  | — | % |  | (173.8 | )%
| Tax exempt municipal bond interest | (1.4 | )% |  | (1.9 | )% |  | (0.8 | )%
| Other, net | 0.4 | % |  | 0.3 | % |  | (0.8 | )%
| Effective tax provision (benefit) rate | 54.7 | % |  | 33.5 | % |  | (140.3 | )%
Reconciliation of unrecognized tax benefits | A reconciliation of the beginning and ending amount of unrecognized tax benefits is shown in table 12.7.
| Table | 12.7 |  |  |  |  |  |
Unrecognized tax benefits reconciliation | (in thousands) |  | 2017 |  | 2016 |  | 2015
Balance at beginning of year |  | $ | 108,245 |  |  | $ | 107,120 |  |  | $ | 106,230 |
Additions based on tax positions related to the current year |  | — |  |  | — |  |  | — |
| Additions for tax positions of prior years |  | 35,003 |  |  | 1,125 |  |  | 890 |
| Reductions for tax positions of prior years |  | (427 | ) |  | — |  |  | — |
| Settlements |  | — |  |  | — |  |  | — |
| Balance at end of year |  | $ | 142,821 |  |  | $ | 108,245 |  |  | $ | 107,120 |

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- Definition Tabular disclosure of the components of income tax expense attributable to continuing operations for each year presented including, but not limited to: current tax expense (benefit), deferred tax expense (benefit), investment tax credits, government grants, the benefits of operating loss carryforwards, tax expense that results from allocating certain tax benefits either directly to contributed capital or to reduce goodwill or other noncurrent intangible assets of an acquired entity, adjustments of a deferred tax liability or asset for enacted changes in tax laws or rates or a change in the tax status of the entity, and adjustments of the beginning-of-the-year balances of a valuation allowance because of a change in circumstances that causes a change in judgment about the realizability of the related deferred tax asset in future years. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 9 -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32639-109319 + Details
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- Definition Tabular disclosure for tax positions taken in the tax returns filed or to be filed for which it is more likely than not that the tax position will not be sustained upon examination by taxing authorities and other income tax contingencies. Includes, but is not limited to, interest and penalties, reconciliation of unrecognized tax benefits, unrecognized tax benefits that would affect the effective tax rate, tax years that remain subject to examination by tax jurisdictions, and information about positions for which it is reasonably possible that amounts unrecognized will significantly change within 12 months. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 15A -URI http://asc.fasb.org/extlink&oid=84230637&loc=SL6600010-109319 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 15 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32718-109319 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 19 -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32840-109319 + Details
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