Investments - Summary of Securities Available for Sale (Detail) - USD ($) $ in Thousands |
12 Months Ended | |
|---|---|---|
Dec. 31, 2017 |
Dec. 31, 2016 |
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| Investments Debt And Equity Securities [Abstract] | ||
| Proceeds from sales and maturities (fair value) | $ 206,010 | $ 226,191 |
| Gross realized gains | 2,873 | 2,329 |
| Gross realized losses | $ (303) | $ (35) |
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- Definition This item represents the gross profit realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition This item represents the gross loss realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- References No definition available.
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- Definition The cash inflow associated with the sale or maturity (principal being due) of securities not classified as either held-to-maturity securities or trading securities which are classified as available-for-sale securities. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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