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Investments (Unrealized Gains on Investments) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Net unrealized gains	$ 149,612	$ 82,874	$ 45,136
Deferred income tax expense	(52,364)	(29,006)	(15,797)
Net unrealized gains, net deferred income tax	97,248	53,868	29,339
Cumulative effect adjustment due to adoption of OTTI accounting guidance, net of deferred income tax	0	0	2,380
Net unrealized gains, in OCI, net of deferred income tax	97,248	53,868	31,719
Income in net unrealized gains in OCI, net of deferred income tax	43,380	24,529	86,554
AFS Fixed Maturity Securities [Member]
Net unrealized gains	130,517	56,754	19,413
Equity Securities [Member]
Net unrealized gains	13,529	11,597	15,874
Available-for-sale Securities [Member]
Net unrealized gains	144,046	68,351	35,287
Held To Maturity Fixed Maturity Securities Member
Net unrealized gains	5,566	14,523	9,849
Total HTM securities [Member]
Net unrealized gains	$ 5,566	$ 14,523	$ 9,849

X

- Definition

Cumulative-effect adjustment to retained earnings, net of tax, due to adoption of other- than-temporary impairment guidance under ASC 320.

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No definition available.

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X

- Definition

Tax effect of unrealized gain (loss) on investments in accumulated other comprehensive income.

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No definition available.

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X

- Definition

This item represents the net unrealized gains (losses) on investments in other comprehensive income, net of deferred income tax.

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No definition available.

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- Definition

This item represents the net unrealized gains (losses) on investments in accumulated other comprehensive income, net of deferred income tax, prior to the impact of cumulative effect adjustment due to adoption of accounting literature.

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No definition available.

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- Definition

This amount is equal to the sum of: (i) the non-credit portion of other-than-temporary impairment losses on fixed maturity securities recognized in other comprehensive income, net of tax, including subsequent changes to these securities such as amortization on HTM securities or subsequent sales; and (ii) the change in net unrealized gains or losses on investment securities, after tax, excluding non-credit other-than-temporary impairment charges during the period.

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No definition available.

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- Definition

The difference between the fair value and the carrying value, or in the comparative fair values, of investments, not including unrealized gains or losses on securities separately or otherwise categorized as trading, available-for-sale, or held-to-maturity, held at each balance sheet date and included in other comprehensive income

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No definition available.

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