Realized Gains and Losses, Excluding Net Other-Than-Temporary Impairment Losses Recognized in Earnings (Detail) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2016	Mar. 31, 2015
Gain (Loss) on Investments [Line Items]
Net realized gains (losses)	$ 1,597	$ 5,596
Fixed maturities
Gain (Loss) on Investments [Line Items]
Gains	2,548	1,174
Losses	(1,127)	(572)
Net realized gains (losses)	1,421	602
Short-term investments
Gain (Loss) on Investments [Line Items]
Gains	268	8
Losses	(83)	(162)
Net realized gains (losses)	185	(154)
Equity Securities
Gain (Loss) on Investments [Line Items]
Gains	609	6,325
Losses	(618)	(1,177)
Net realized gains (losses)	$ (9)	$ 5,148

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
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 9
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27357-111563

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This item represents the difference between the gross realized gains and losses realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 45
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=49167202&loc=d3e26805-111562

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