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v3.19.2

Segment Information - Summary of Operating Results by Segment (Details) $ in Thousands | 3 Months Ended | 6 Months Ended
--- | --- | ---
Jun. 30, 2019 USD ($) State | Jun. 30, 2018 USD ($) | Jun. 30, 2019 USD ($) Subsidiary segment State | Jun. 30, 2018 USD ($)
Segment Reporting [Abstract] |  |  |  |
Number of insurance companies | Subsidiary |  |  | 14 |
Number of states in which company operates | State | 11 |  | 11 |
Number of reportable segments | segment |  |  | 1 |
Segment Reporting Information [Line Items] |  |  |  |
Net premiums earned | $ 888,776 | $ 833,959 | $ 1,759,021 | $ 1,642,043
Losses and loss adjustment expenses | 656,577 | 605,547 | 1,286,993 | 1,237,781
Underwriting expenses | 217,000 | 202,500 | 432,900 | 408,800
Underwriting gain (loss) | 15,200 | 26,000 | 39,100 | (4,600)
Net investment income | 35,032 | 34,786 | 69,206 | 66,296
Net realized investment gains (losses) | 53,329 | 14,290 | 164,403 | (44,445)
Other | 2,350 | 2,356 | 4,600 | 4,681
Interest expense | (4,266) | (4,256) | (8,522) | (8,522)
Pre-tax income | 101,595 | 73,246 | 268,764 | 13,547
Net income | 83,250 | 60,180 | 219,117 | 17,573
Property and Casualty Lines [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Net premiums earned | 881,800 | 826,200 | 1,744,900 | 1,626,400
Losses and loss adjustment expenses | 653,300 | 601,500 | 1,280,100 | 1,229,900
Underwriting expenses | 213,500 | 198,700 | 426,000 | 401,200
Underwriting gain (loss) | 15,000 | 26,000 | 38,800 | (4,700)
Other Segments [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Net premiums earned | 7,000 | 7,800 | 14,100 | 15,600
Losses and loss adjustment expenses | 3,300 | 4,000 | 6,900 | 7,900
Underwriting expenses | 3,500 | 3,800 | 6,900 | 7,600
Underwriting gain (loss) | $ 200 | $ 0 | $ 300 | $ 100

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