Investment in Securities - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017
Investment [Line Items]
Securities transferred from held-to-maturity to available-for-sale	$ 34,690	$ 25,266
Unrealized loss, transferred securities	0	(6,000)
Assets held by insurance regulators	48,068	47,556
Carrying value of bonds pledged	168,118	$ 63,386
Isolated Event
Investment [Line Items]
Securities transferred from held-to-maturity to available-for-sale	$ 38,381

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- Definition

Carrying amount of cash and investment securities on deposit with state regulatory authorities in connection with capital requirements.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 825
-Section 50
-Paragraph 1A
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- Definition

Amount of investment in debt security, measured at amortized cost, transferred to investment in debt security, measured at fair value, with change in fair value recognized in other comprehensive income (available-for-sale) and net income (trading).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
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- Definition

Amount before tax and reclassification adjustments of unrealized holding gain (loss) related to transfers of securities into the available-for-sale classification and out of the held-to-maturity classification.

+ References

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- Definition

Sum of the carrying amounts as of the date of the latest financial statement presented of securities which are owned but transferred to another party to serve as collateral to partially or fully secure a debt obligation, repurchase agreement or other current or potential obligation, and for which the transferee is not permitted to sell or re-pledge them to an unrelated party.

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