Fair Value (Details - Level 3 inputs and transfers) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Balance, beginning of year	$ 500,286,000	$ 291,769,000
Realized and unrealized investment gains (losses) included in net (loss) income	(45,942,000)	29,239,000
Purchases and issuances	350,105,000
Sales and settlements	235,140,000
Net purchases, sales and settlements		172,182,000
Net transfers (out of)/ into Level 3	40,180,000	7,096,000
Balance, end of year	609,489,000	500,286,000
Change in unrealized investment gains (losses) relating to assets held at the end of period	(3,281,000)	(4,397,000)
Fair value of financial instrument liabilities [Line Items]
Debt related to senior notes	750,000,000	750,000,000
Debt related to capital efficient notes	70,989,000	70,989,000
[FundsHeldDirectlyManagedMember]
Fair Value - Other Details [Line Items]
Cash and cash equivalents	176,300,000	129,200,000
Accrued investment income	13,700,000	19,900,000
Other net assets	20,400,000	80,100,000
[FundsHeldDirectlyManagedMember] | [FixedMaturitiesMember]
Fair Value - Other Details [Line Items]
Transfers into Level 3		16,900,000
[TradingSecuritiesMember]
Fair Value - Other Details [Line Items]
Aggregate carrying amount of other invested assets not carried at fair value	267,600,000	241,000,000
[TradingSecuritiesMember] | [FixedMaturitiesMember]
Fair Value - Other Details [Line Items]
Transfers out of Level 3		17,900,000
Transfers into Level 3	40,200,000
Realized loss on maturity of catastrophe bond	39,200,000
[TradingSecuritiesMember] | [DerivativeMember]
Fair Value - Other Details [Line Items]
Transfers out of Level 3		(8,200,000)
[EstimateOfFairValueFairValueDisclosureMember]
Fair value of financial instrument liabilities [Line Items]
Debt related to senior notes	781,449,000	781,950,000
Debt related to capital efficient notes	55,678,000	59,261,000
[CarryingReportedAmountFairValueDisclosureMember]
Fair value of financial instrument liabilities [Line Items]
Debt related to senior notes	750,000,000	750,000,000
Debt related to capital efficient notes	63,384,000	63,384,000
[FixedMaturitiesMember]
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Balance, beginning of year	345,535,000	197,593,000
Realized and unrealized investment gains (losses) included in net (loss) income	(15,008,000)	23,061,000
Purchases and issuances	279,119,000
Sales and settlements	169,296,000
Net purchases, sales and settlements		142,817,000
Net transfers (out of)/ into Level 3	40,180,000	(17,936,000)
Balance, end of year	480,530,000	345,535,000
Change in unrealized investment gains (losses) relating to assets held at the end of period	22,656,000	(3,658,000)
[FixedMaturitiesMember] | [USStatesAndPoliticalSubdivisionsMember]
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Balance, beginning of year	55,124,000	4,286,000
Realized and unrealized investment gains (losses) included in net (loss) income	5,288,000	2,379,000
Purchases and issuances	51,163,000
Sales and settlements	160,000
Net purchases, sales and settlements		52,745,000
Net transfers (out of)/ into Level 3	0	(4,286,000)
Balance, end of year	111,415,000	55,124,000
Change in unrealized investment gains (losses) relating to assets held at the end of period	5,288,000	(126,000)
[FixedMaturitiesMember] | [CorporateDebtSecuritiesMember]
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Balance, beginning of year	76,982,000	15,041,000
Realized and unrealized investment gains (losses) included in net (loss) income	(36,617,000)	38,000
Purchases and issuances	41,246,000
Sales and settlements	10,091,000
Net purchases, sales and settlements		72,653,000
Net transfers (out of)/ into Level 3	40,180,000	(10,750,000)
Balance, end of year	111,700,000	76,982,000
Change in unrealized investment gains (losses) relating to assets held at the end of period	2,430,000	38,000
[FixedMaturitiesMember] | [AssetBackedSecuritiesSecuritizedLoansAndReceivablesMember]
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Balance, beginning of year	213,139,000	99,952,000
Realized and unrealized investment gains (losses) included in net (loss) income	15,161,000	20,692,000
Purchases and issuances	182,090,000
Sales and settlements	152,975,000
Net purchases, sales and settlements		95,395,000
Net transfers (out of)/ into Level 3	0	(2,900,000)
Balance, end of year	257,415,000	213,139,000
Change in unrealized investment gains (losses) relating to assets held at the end of period	14,938,000	(3,331,000)
[FixedMaturitiesMember] | [ResidentialMortgageBackedSecuritiesMember]
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Balance, beginning of year	0	77,440,000
Realized and unrealized investment gains (losses) included in net (loss) income	1,385,000	191,000
Purchases and issuances	4,212,000
Sales and settlements	5,597,000
Net purchases, sales and settlements		(77,631,000)
Net transfers (out of)/ into Level 3	0	0
Balance, end of year	0	0
Change in unrealized investment gains (losses) relating to assets held at the end of period	0	0
[FixedMaturitiesMember] | [CommercialMortgageBackedSecuritiesMember]
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Balance, beginning of year	290,000	874,000
Realized and unrealized investment gains (losses) included in net (loss) income	(225,000)	(239,000)
Purchases and issuances	408,000
Sales and settlements	473,000
Net purchases, sales and settlements		(345,000)
Net transfers (out of)/ into Level 3	0	0
Balance, end of year	0	290,000
Change in unrealized investment gains (losses) relating to assets held at the end of period	0	(239,000)
[EquitySecuritiesMember]
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Balance, beginning of year	43,413,000	38,103,000
Realized and unrealized investment gains (losses) included in net (loss) income	1,418,000	337,000
Purchases and issuances	9,523,000
Sales and settlements	38,189,000
Net purchases, sales and settlements		4,973,000
Net transfers (out of)/ into Level 3	0	0
Balance, end of year	16,165,000	43,413,000
Change in unrealized investment gains (losses) relating to assets held at the end of period	(433,000)	1,115,000
[EquitySecuritiesMember] | [FinanceMember]
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Balance, beginning of year	2,486,000	2,488,000
Realized and unrealized investment gains (losses) included in net (loss) income	223,000	(696,000)
Purchases and issuances	9,523,000
Sales and settlements	2,562,000
Net purchases, sales and settlements		694,000
Net transfers (out of)/ into Level 3	0	0
Balance, end of year	9,670,000	2,486,000
Change in unrealized investment gains (losses) relating to assets held at the end of period	(4,000)	(2,000)
[EquitySecuritiesMember] | [IndustrialsMember]
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Balance, beginning of year		805,000
Realized and unrealized investment gains (losses) included in net (loss) income		(84,000)
Net purchases, sales and settlements		(721,000)
Net transfers (out of)/ into Level 3		0
Balance, end of year		0
Change in unrealized investment gains (losses) relating to assets held at the end of period		0
[EquitySecuritiesMember] | [MutualFundsAndExchangeTradedFundsMember]
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Balance, beginning of year	40,927,000	34,810,000
Realized and unrealized investment gains (losses) included in net (loss) income	1,195,000	1,117,000
Purchases and issuances	0
Sales and settlements	35,627,000
Net purchases, sales and settlements		5,000,000
Net transfers (out of)/ into Level 3	0	0
Balance, end of year	6,495,000	40,927,000
Change in unrealized investment gains (losses) relating to assets held at the end of period	(429,000)	1,117,000
[OtherInvestedAssetsMember]
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Balance, beginning of year	78,324,000	16,454,000
Realized and unrealized investment gains (losses) included in net (loss) income	(27,244,000)	14,593,000
Purchases and issuances	57,471,000
Sales and settlements	11,524,000
Net purchases, sales and settlements		39,111,000
Net transfers (out of)/ into Level 3	0	8,166,000
Balance, end of year	97,027,000	78,324,000
Change in unrealized investment gains (losses) relating to assets held at the end of period	(21,951,000)	6,854,000
[OtherInvestedAssetsMember] | [DerivativeMember]
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Balance, beginning of year	(7,954,000)	(9,361,000)
Realized and unrealized investment gains (losses) included in net (loss) income	(3,546,000)	12,939,000
Purchases and issuances	(4,103,000)
Sales and settlements	(21,225,000)
Issuances	5,100,000
Settlements	21,200,000
Net purchases, sales and settlements		(19,698,000)
Net transfers (out of)/ into Level 3	0	8,166,000
Balance, end of year	5,622,000	(7,954,000)
Change in unrealized investment gains (losses) relating to assets held at the end of period	2,548,000	4,348,000
[OtherInvestedAssetsMember] | [OtherInvestedAssetsOtherAssetsMember]
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Balance, beginning of year	86,278,000	25,815,000
Realized and unrealized investment gains (losses) included in net (loss) income	(23,698,000)	1,654,000
Purchases and issuances	61,574,000
Sales and settlements	32,749,000
Net purchases, sales and settlements		58,809,000
Net transfers (out of)/ into Level 3	0	0
Balance, end of year	91,405,000	86,278,000
Change in unrealized investment gains (losses) relating to assets held at the end of period	(24,499,000)	2,506,000
[FundsHeldDirectlyManagedInvestmentMember]
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Balance, beginning of year	33,014,000	39,619,000
Realized and unrealized investment gains (losses) included in net (loss) income	(4,039,000)	(8,752,000)
Purchases and issuances	0
Sales and settlements	13,208,000
Net purchases, sales and settlements		(14,719,000)
Net transfers (out of)/ into Level 3	0	16,866,000
Balance, end of year	15,767,000	33,014,000
Change in unrealized investment gains (losses) relating to assets held at the end of period	(3,553,000)	(8,708,000)
[FundsHeldDirectlyManagedInvestmentMember] | [OtherInvestedAssetsFundsHeldDirectlyManagedMember]
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Balance, beginning of year	20,528,000	35,685,000
Realized and unrealized investment gains (losses) included in net (loss) income	(3,855,000)	(3,842,000)
Purchases and issuances	0
Sales and settlements	1,240,000
Net purchases, sales and settlements		(11,315,000)
Net transfers (out of)/ into Level 3	0	0
Balance, end of year	15,433,000	20,528,000
Change in unrealized investment gains (losses) relating to assets held at the end of period	(3,519,000)	(3,824,000)
[FundsHeldDirectlyManagedInvestmentMember] | [USStatesAndPoliticalSubdivisionsMember]
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Balance, beginning of year	368,000	375,000
Realized and unrealized investment gains (losses) included in net (loss) income	(34,000)	(7,000)
Purchases and issuances	0
Sales and settlements	0
Net purchases, sales and settlements		0
Net transfers (out of)/ into Level 3	0	0
Balance, end of year	334,000	368,000
Change in unrealized investment gains (losses) relating to assets held at the end of period	(34,000)	(7,000)
[FundsHeldDirectlyManagedInvestmentMember] | [NonUsSovereignGovernmentSupranationalAndGovernmentRelatedDebtSecuritiesMember]
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Balance, beginning of year		3,417,000
Realized and unrealized investment gains (losses) included in net (loss) income		(13,000)
Net purchases, sales and settlements		(3,404,000)
Net transfers (out of)/ into Level 3		0
Balance, end of year		0
Change in unrealized investment gains (losses) relating to assets held at the end of period		0
[FundsHeldDirectlyManagedInvestmentMember] | [AssetBackedSecuritiesMember]
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Balance, beginning of year	12,118,000	142,000
Realized and unrealized investment gains (losses) included in net (loss) income	(150,000)	(4,890,000)
Purchases and issuances	0
Sales and settlements	11,968,000
Net purchases, sales and settlements		0
Net transfers (out of)/ into Level 3	0	16,866,000
Balance, end of year	0	12,118,000
Change in unrealized investment gains (losses) relating to assets held at the end of period	0	(4,877,000)
[ShortTermInvestmentsMember]
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Balance, beginning of year	0
Realized and unrealized investment gains (losses) included in net (loss) income	(1,069,000)
Purchases and issuances	3,992,000
Sales and settlements	2,923,000
Net transfers (out of)/ into Level 3	0
Balance, end of year	0
Change in unrealized investment gains (losses) relating to assets held at the end of period	$ 0