Investments - Summary of Amortized Cost, Gross Unrealized Gains and Losses, and Estimated Fair Value of Equity Securities (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Cost	$ 45,671	$ 54,282
Gross Unrealized Gain	1,059	6,383
Gross Unrealized Loss	(5,587)	(709)
Estimated Fair Value	$ 41,143	$ 59,956

Amount of unrealized gain on investment in equity security measured at fair value with change in fair value recognized in net income.

No definition available.

+ Details

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- Definition

Amount of unrealized loss on investment in equity security measured at fair value with change in fair value recognized in net income.

+ References

No definition available.

+ Details

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- Definition

Amount of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 45
-Paragraph 1A
-URI http://asc.fasb.org/extlink&oid=99377092&loc=SL75136599-209740

+ Details

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- Definition

Cost of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI). Excludes equity method investment and investment in equity security without readily determinable fair value.

+ References

No definition available.

+ Details

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