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Schedule II. Condensed Financial Information of Registrant - Condensed Statements of Income (Detail) - USD ($) $ in Thousands | 3 Months Ended | 12 Months Ended
--- | --- | ---
Dec. 31, 2015 | Sep. 30, 2015 | Jun. 30, 2015 | Mar. 31, 2015 | Dec. 31, 2014 | Sep. 30, 2014 | Jun. 30, 2014 | Mar. 31, 2014 | Dec. 31, 2015 | Dec. 31, 2014 | Dec. 31, 2013
Revenues |  |  |  |  |  |  |  |  |  |  |
Net investment income | $ 7,256 | $ 6,923 | $ 6,890 | $ 6,833 | $ 7,166 | $ 6,495 | $ 6,845 | $ 6,708 | $ 27,902 | $ 27,214 | $ 27,029
Fee and other income |  |  |  |  |  |  |  |  | 316 | 361 | 536
Total revenues | 101,760 | 97,470 | 99,936 | 101,788 | 104,886 | 102,336 | 100,624 | 96,173 | 400,954 | 404,019 | 356,335
Expenses |  |  |  |  |  |  |  |  |  |  |
Total expenses |  |  |  |  |  |  |  |  | 299,987 | 330,270 | 297,131
Income tax expense (benefit) |  |  |  |  |  |  |  |  | 30,505 | 20,083 | 15,567
Net income | $ 23,073 | $ 17,940 | $ 14,319 | $ 15,130 | $ 16,865 | $ 13,479 | $ 12,773 | $ 10,549 | 70,462 | 53,666 | 43,637
Parent Company [Member] |  |  |  |  |  |  |  |  |  |  |
Revenues |  |  |  |  |  |  |  |  |  |  |
Net investment income |  |  |  |  |  |  |  |  | 854 | 1,541 | 1,051
Fee and other income |  |  |  |  |  |  |  |  | 5,893 | 5,368 | 5,453
Total revenues |  |  |  |  |  |  |  |  | 6,747 | 6,909 | 6,504
Expenses |  |  |  |  |  |  |  |  |  |  |
Other operating costs |  |  |  |  |  |  |  |  | 6,747 | 6,909 | 6,504
Total expenses |  |  |  |  |  |  |  |  | 6,747 | 6,909 | 6,504
Income (loss) before income taxes and equity in earnings of subsidiaries |  |  |  |  |  |  |  |  | 0 | 0 | 0
Income tax expense (benefit) |  |  |  |  |  |  |  |  | (57) | (13) | 6
Gain (loss) before equity in earnings of subsidiaries |  |  |  |  |  |  |  |  | 57 | 13 | (6)
Equity in net income of subsidiaries |  |  |  |  |  |  |  |  | 70,405 | 53,653 | 43,643
Net income |  |  |  |  |  |  |  |  | $ 70,462 | $ 53,666 | $ 43,637

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