Change In Net Unrealized Gains/(Losses) (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012		Mar. 31, 2011
Gross unrealized gains (losses)	$ 13,767		$ 221
Deferred income tax	4,818		183
Change in net unrealized gains (losses) on investments, net of tax	8,949	[1]	38	[1]
Fixed maturities
Gross unrealized gains (losses)	9,128		(3,640)
Equity Securities
Gross unrealized gains (losses)	$ 4,639		$ 3,861

[1] Disclosure of reclassification amount, net of tax: Unrealized gains (losses) on investments arising during period $ 9,421 $ 183 Reclassification adjustment for net realized gains (losses) included in net income (638 ) (123 ) Reclassification adjustment for other-than-temporary impairment losses recognized in net income 166 (22 ) Change in net unrealized gains (losses) on investments, net of tax $ 8,949 $ 38