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Comprehensive Income and Accumulated Other Comprehensive Income - Other Comprehensive Income (Detail) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2015 | Dec. 31, 2014 | Dec. 31, 2013
Equity [Abstract] |  |  |
Unrealized gain (loss) on available-for-sale securities, Pre-tax Amount | $ (2,572) | $ 10,133 | $ (11,724)
Change in unrealized losses on available-for-sale securities with OTTI, Pre-Tax Amount | 176 |  | 222
Less amortization of differences between fair value and amortized cost for fixed maturity security transfer, Pre-tax Amount | (40) | (44) | (75)
Less reclassification adjustment for gains realized in net income, Pre-Tax Amount | 2,093 | 842 | 386
Net unrealized gain loss, Pre-Tax Amount | (343) | 10,931 | (11,191)
Other comprehensive income, Pre-Tax Amount | (343) | 10,931 | (11,191)
Unrealized gain loss on available-for-sale securities, Tax Expense | (900) | 3,546 | (4,104)
Change in unrealized losses on available-for-sale securities with OTTI, Tax Expense | 62 |  | 78
Less amortization of differences between fair value and amortized cost for fixed maturity security transfer, Tax Expense | (14) | (15) | (26)
Less reclassification adjustment for gains realized in net income, Tax Expense | 732 | 295 | 135
Net unrealized gain loss, Tax Expense | (120) | 3,826 | (3,917)
Other comprehensive income, Tax Expense | (120) | 3,826 | (3,917)
Unrealized gain (loss) on available-for-sale securities, Net-of-Tax Amount | (1,672) | 6,587 | (7,620)
Change in unrealized losses on available-for-sale securities with OTTI, Net-of-Tax Amount | 114 |  | 144
Less amortization of differences between fair value and amortized cost for fixed maturity security transfer, Net-of-Tax Amount | (26) | (29) | (49)
Reclassification adjustment for gains realized in net income, Net-of-Tax Amount | 1,361 | 547 | 251
Net unrealized gain loss, Net-of-Tax Amount | (223) | 7,105 | (7,274)
Other comprehensive income, Net-of-Tax Amount | $ (223) | $ 7,105 | $ (7,274)

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