Realized Gains and Losses (Detail) (USD $) In Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Gain (Loss) on Investments [Line Items]
Net realized gains (losses)	$ 3,006	$ 11,020	$ 1,618	$ 17,133
Fixed maturities
Gain (Loss) on Investments [Line Items]
Gains	4,443	11,281	7,312	17,651
(Losses)	(2,277)	(26)	(6,534)	(283)
Net realized gains (losses)	2,166	11,255	778	17,368
Equity Securities
Gain (Loss) on Investments [Line Items]
Gains	840		840
(Losses)		(235)		(235)
Net realized gains (losses)	$ 840	$ (235)	$ 840	$ (235)

The net realized gains or losses on investments during the period, not including gains or losses on securities separately or otherwise categorized as trading, available-for-sale, or held-to-maturity.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 04
-Paragraph 3
-Subparagraph a
-Article 7

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 225
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04.3(a))
-URI http://asc.fasb.org/extlink&oid=6879464&loc=d3e573970-122913

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 325
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6485959&loc=d3e22529-158502

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Balance Type:	credit
Period Type:	duration