Schedule of Change in Unrealized net Capital Gains and Losses (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Change In Unrealized Gain Loss Recognized In Accumulated Other Comprehensive Income Loss [Line Items]
Change in unrealized net capital gains and losses	$ 116,070	$ (343,401)	$ 174,028
Amounts recognized for:
Insurance reserves	(88,985)	192,620	(90,058)
DAC and DSI	1,058	10,295	(9,162)
Amounts recognized	(87,927)	202,915	(99,220)
Deferred income taxes	(9,850)	49,170	(26,182)
Increase (decrease) in unrealized net capital gains and losses, after-tax	18,293	(91,316)	48,626
EMA limited partnerships
Change In Unrealized Gain Loss Recognized In Accumulated Other Comprehensive Income Loss [Line Items]
Change in unrealized net capital gains and losses		(127)	97
Fixed income securities
Change In Unrealized Gain Loss Recognized In Accumulated Other Comprehensive Income Loss [Line Items]
Change in unrealized net capital gains and losses	154,469	(351,008)	163,066
Equity securities
Change In Unrealized Gain Loss Recognized In Accumulated Other Comprehensive Income Loss [Line Items]
Change in unrealized net capital gains and losses	(38,400)	7,735	10,861
Short-term investments
Change In Unrealized Gain Loss Recognized In Accumulated Other Comprehensive Income Loss [Line Items]
Change in unrealized net capital gains and losses	$ 1	$ (1)	$ 4

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Represents change in Deferred Policy Acquisition Costs and Deferred Sales Inducement Costs adjustment included in accumulated other comprehensive income (loss) during the period.

+ References

No definition available.

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- Definition

Represents change in insurance reserve adjustment included in accumulated other comprehensive income (loss) during the period.

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No definition available.

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- Definition

Represents change in accumulated adjustments to Deferred Policy Acquisition Costs, Deferred Sales Inducement Costs, and insurance reserves related to unrealized capital gains and losses during the period.

+ References

No definition available.

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- Definition

This item represents the pretax change in net unrealized holding gain (loss) on available-for-sale securities that has been included in accumulated other comprehensive income, a separate component of shareholders' equity, during the period.

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The change in unrealized holding gain (loss), net of tax, on available-for-sale securities included in a separate component of shareholders' equity during the period.

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- Definition

This item represents the tax effects occurring during the period which are related to the net unrealized gain (loss) resulting from changes in the fair [carrying] value during the period of available-for-sale securities. Such tax affects would have been charged or credited directly to other comprehensive income or to related components of shareholders' equity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

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Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

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