Consolidated Condensed Schedule Of Investments (Financial Derivatives) (USD $)	12 Months Ended
	Dec. 31, 2013 contracts		Dec. 31, 2012 contracts
Investment Holdings, Other than Securities [Line Items]
Derivative Asset	$ 59,664,000	[1]	$ 48,504,000	[1]
Derivative Liabilities	(44,791,000)	[1]	(15,212,000)	[1]
Net cost	50,533,000		65,860,000
Net proceeds	(29,746,000)		(13,171,000)
Eurodollar Future [Member]
Investment Holdings, Other than Securities [Line Items]
Future contract notional	1,000,000		1,000,000
Future contract	1		1
U.S. Treasury Note Futures [Member]
Investment Holdings, Other than Securities [Line Items]
Number of contracts	1,847
Financial Derivatives - Assets [Member]
Investment Holdings, Other than Securities [Line Items]
Derivative Asset	59,664,000	[2]	48,504,000	[2]
Investment owned as a percentage of equity	9.53%	[2],[3]	9.58%	[2],[3]
Net cost	50,533,000	[2]	65,860,000	[2]
Financial Derivatives - Assets [Member] | Long Credit Default Swap On Corporate Bond Indices [Member]
Investment Holdings, Other than Securities [Line Items]
Primary risk exposure	Credit	[2],[4]
Notional - asset	70,425,000	[2],[4]
Range of expiration dates	2018-12	[2],[4]
Derivative Asset	14,273,000	[2],[4]
Net cost	13,248,000	[2],[4]
Financial Derivatives - Assets [Member] | Long Interest Rate Swaps [Member]
Investment Holdings, Other than Securities [Line Items]
Primary risk exposure	Interest Rates	[2],[5]
Notional - asset	153,100,000	[2],[5]
Derivative Asset	1,978,000	[2],[5]
Financial Derivatives - Assets [Member] | Long Interest Rate Swaps [Member] | Minimum [Member]
Investment Holdings, Other than Securities [Line Items]
Range of expiration dates	2018-07	[2],[5]
Financial Derivatives - Assets [Member] | Long Interest Rate Swaps [Member] | Maximum [Member]
Investment Holdings, Other than Securities [Line Items]
Range of expiration dates	2023-09	[2],[5]
Financial Derivatives - Assets [Member] | Long Credit Default Swap On Asset Backed Indices [Member]
Investment Holdings, Other than Securities [Line Items]
Primary risk exposure	Credit	[2],[6]	Credit	[2],[6]
Notional - asset	1,990,000	[2],[6]	10,166,000	[2],[6]
Range of expiration dates	2037-12	[2],[6]
Derivative Asset	61,000	[2],[6]	765,000	[2],[6]
Net cost			135,000	[2],[6]
Net proceeds	(217,000)	[2],[6]
Financial Derivatives - Assets [Member] | Long Credit Default Swap On Asset Backed Indices [Member] | Minimum [Member]
Investment Holdings, Other than Securities [Line Items]
Range of expiration dates			2036-06	[2],[6]
Financial Derivatives - Assets [Member] | Long Credit Default Swap On Asset Backed Indices [Member] | Maximum [Member]
Investment Holdings, Other than Securities [Line Items]
Range of expiration dates			2037-12	[2],[6]
Financial Derivatives - Assets [Member] | Long Total Return Swaps [Member]
Investment Holdings, Other than Securities [Line Items]
Primary risk exposure	Equity Market	[2],[7]
Notional - asset	3,044,000	[2],[7]
Derivative Asset	4,000	[2],[7]
Financial Derivatives - Assets [Member] | Long Total Return Swaps [Member] | Minimum [Member]
Investment Holdings, Other than Securities [Line Items]
Range of expiration dates	2014-06	[2],[7]
Financial Derivatives - Assets [Member] | Long Total Return Swaps [Member] | Maximum [Member]
Investment Holdings, Other than Securities [Line Items]
Range of expiration dates	2015-06	[2],[7]
Financial Derivatives - Assets [Member] | Short Credit Default Swap On Asset Backed Securities [Member]
Investment Holdings, Other than Securities [Line Items]
Primary risk exposure	Credit	[2],[8]	Credit	[2],[8]
Notional - asset	(23,426,000)	[2],[8]	(42,121,000)	[2],[8]
Derivative Asset	16,646,000	[2],[8]	36,031,000	[2],[8]
Financial Derivatives - Assets [Member] | Short Credit Default Swap On Asset Backed Securities [Member] | Minimum [Member]
Investment Holdings, Other than Securities [Line Items]
Range of expiration dates	2034-09	[2],[8]	2034-09	[2],[8]
Financial Derivatives - Assets [Member] | Short Credit Default Swap On Asset Backed Securities [Member] | Maximum [Member]
Investment Holdings, Other than Securities [Line Items]
Range of expiration dates	2036-05	[2],[8]	2036-05	[2],[8]
Financial Derivatives - Assets [Member] | Short Credit Default Swap On Asset Backed Indices [Member]
Investment Holdings, Other than Securities [Line Items]
Primary risk exposure	Credit	[2],[9]	Credit	[2],[9]
Notional - asset	(72,422,000)	[2],[9]	(66,829,000)	[2],[9]
Derivative Asset	4,876,000	[2],[9]	11,703,000	[2],[9]
Financial Derivatives - Assets [Member] | Short Credit Default Swap On Asset Backed Indices [Member] | Minimum [Member]
Investment Holdings, Other than Securities [Line Items]
Range of expiration dates	2046-05	[2],[9]	2046-05	[2],[9]
Financial Derivatives - Assets [Member] | Short Credit Default Swap On Asset Backed Indices [Member] | Maximum [Member]
Investment Holdings, Other than Securities [Line Items]
Range of expiration dates	2063-05	[2],[9]	2052-10	[2],[9]
Financial Derivatives - Assets [Member] | Short Interest Rate Swaps [Member]
Investment Holdings, Other than Securities [Line Items]
Primary risk exposure	Interest Rates	[10],[2]	Interest Rates	[10],[2]
Notional - asset	(840,600,000)	[10],[2]	(18,900,000)	[10],[2]
Range of expiration dates			2017-10	[10],[2]
Derivative Asset	21,575,000	[10],[2]	5,000	[10],[2]
Financial Derivatives - Assets [Member] | Short Interest Rate Swaps [Member] | Minimum [Member]
Investment Holdings, Other than Securities [Line Items]
Range of expiration dates	2016-11	[10],[2]
Financial Derivatives - Assets [Member] | Short Interest Rate Swaps [Member] | Maximum [Member]
Investment Holdings, Other than Securities [Line Items]
Range of expiration dates	2043-08	[10],[2]
Financial Derivatives - Assets [Member] | Short Total Return Swaps [Member]
Investment Holdings, Other than Securities [Line Items]
Primary risk exposure	Equity Market	[2],[7]
Notional - asset	(23,000)	[2],[7]
Range of expiration dates	2015-09	[2],[7]
Derivative Asset	0	[2],[7]
Financial Derivatives - Assets [Member] | Swap [Member]
Investment Holdings, Other than Securities [Line Items]
Derivative Asset	59,413,000	[2]	48,504,000	[2]
Investment owned as a percentage of equity	9.49%	[2],[3]	9.58%	[2],[3]
Net cost	50,039,000	[2]	65,860,000	[2]
Financial Derivatives - Assets [Member] | Option on CDS on Corporate Bond Indices [Member]
Investment Holdings, Other than Securities [Line Items]
Primary risk exposure	Credit	[11],[2]
Notional - asset	22,588,000	[11],[2]
Range of expiration dates	2014-06	[11],[2]
Derivative Asset	190,000	[11],[2]
Financial Derivatives - Assets [Member] | Interest Rate Fixed Swaption [Member]
Investment Holdings, Other than Securities [Line Items]
Primary risk exposure	Interest Rates	[12],[2]
Notional - asset	15,000,000	[12],[2]
Range of expiration dates	2014-04	[12],[2]
Derivative Asset	61,000	[12],[2]
Financial Derivatives - Assets [Member] | Put Option [Member]
Investment Holdings, Other than Securities [Line Items]
Derivative Asset	251,000	[2]
Investment owned as a percentage of equity	0.04%	[2],[3]
Net cost	494,000	[2]
Financial Derivatives - Liabilities [Member]
Investment Holdings, Other than Securities [Line Items]
Derivative Liabilities	(44,791,000)	[2]	(15,212,000)	[2]
Investment owned as a percentage of equity	(7.16%)	[2],[3]	(3.00%)	[2],[3]
Net proceeds	(29,746,000)	[2]	(13,171,000)	[2]
Financial Derivatives - Liabilities [Member] | Long Credit Default Swap On Corporate Bond Indices [Member]
Investment Holdings, Other than Securities [Line Items]
Primary risk exposure	Credit	[2],[4]
Notional - liability	4,000,000	[2],[4]
Range of expiration dates	2017-12	[2],[4]
Derivative Liabilities	(1,047,000)	[2],[4]
Net proceeds	(1,200,000)	[2],[4]
Financial Derivatives - Liabilities [Member] | Long Interest Rate Swaps [Member]
Investment Holdings, Other than Securities [Line Items]
Primary risk exposure	Interest Rates	[2],[5]	Interest Rates	[2],[5]
Notional - liability	234,600,000	[2],[5]	2,500,000	[2],[5]
Derivative Liabilities	(2,857,000)	[2],[5]	(32,000)	[2],[5]
Financial Derivatives - Liabilities [Member] | Long Interest Rate Swaps [Member] | Minimum [Member]
Investment Holdings, Other than Securities [Line Items]
Range of expiration dates	2017-10	[2],[5]	2022-11	[2],[5]
Financial Derivatives - Liabilities [Member] | Long Interest Rate Swaps [Member] | Maximum [Member]
Investment Holdings, Other than Securities [Line Items]
Range of expiration dates	2043-07	[2],[5]	2022-12	[2],[5]
Financial Derivatives - Liabilities [Member] | Long Credit Default Swap On Asset Backed Indices [Member]
Investment Holdings, Other than Securities [Line Items]
Primary risk exposure	Credit	[2],[6]	Credit	[2],[6]
Notional - liability	44,082,000	[2],[6]	30,050,000	[2],[6]
Derivative Liabilities	(11,866,000)	[2],[6]	(12,751,000)	[2],[6]
Net proceeds	(14,331,000)	[2],[6]	(12,736,000)	[2],[6]
Financial Derivatives - Liabilities [Member] | Long Credit Default Swap On Asset Backed Indices [Member] | Minimum [Member]
Investment Holdings, Other than Securities [Line Items]
Range of expiration dates	2049-12	[2],[6]	2049-12	[2],[6]
Financial Derivatives - Liabilities [Member] | Long Credit Default Swap On Asset Backed Indices [Member] | Maximum [Member]
Investment Holdings, Other than Securities [Line Items]
Range of expiration dates	2052-10	[2],[6]	2051-02	[2],[6]
Financial Derivatives - Liabilities [Member] | Long Total Return Swaps [Member]
Investment Holdings, Other than Securities [Line Items]
Primary risk exposure	Equity Market	[2],[7]
Notional - liability	47,974,000	[2],[7]
Range of expiration dates	2015-06	[2],[7]
Derivative Liabilities	0	[2],[7]
Financial Derivatives - Liabilities [Member] | Short Credit Default Swap On Asset Backed Securities [Member]
Investment Holdings, Other than Securities [Line Items]
Primary risk exposure	Credit	[2],[8]	Credit	[2],[8]
Notional - liability	(3,000,000)	[2],[8]	(3,000,000)	[2],[8]
Range of expiration dates	2035-03	[2],[8]	2035-03	[2],[8]
Derivative Liabilities	(350,000)	[2],[8]	(1,000)	[2],[8]
Financial Derivatives - Liabilities [Member] | Short Credit Default Swap On Asset Backed Indices [Member]
Investment Holdings, Other than Securities [Line Items]
Primary risk exposure			Credit	[2],[9]
Notional - liability			(7,792,000)	[2],[9]
Derivative Liabilities			(717,000)	[2],[9]
Financial Derivatives - Liabilities [Member] | Short Credit Default Swap On Asset Backed Indices [Member] | Minimum [Member]
Investment Holdings, Other than Securities [Line Items]
Range of expiration dates			2036-06	[2],[9]
Financial Derivatives - Liabilities [Member] | Short Credit Default Swap On Asset Backed Indices [Member] | Maximum [Member]
Investment Holdings, Other than Securities [Line Items]
Range of expiration dates			2037-12	[2],[9]
Financial Derivatives - Liabilities [Member] | Short Credit Default Swaps On Corporate Bond Indices [Member]
Investment Holdings, Other than Securities [Line Items]
Primary risk exposure	Credit	[13],[2]	Credit	[13],[2]
Notional - liability	(337,815,000)	[13],[2]	(67,500,000)	[13],[2]
Range of expiration dates			2017-12	[13],[2]
Derivative Liabilities	(23,902,000)	[13],[2]	(484,000)	[13],[2]
Financial Derivatives - Liabilities [Member] | Short Credit Default Swaps On Corporate Bond Indices [Member] | Minimum [Member]
Investment Holdings, Other than Securities [Line Items]
Range of expiration dates	2016-12	[13],[2]
Financial Derivatives - Liabilities [Member] | Short Credit Default Swaps On Corporate Bond Indices [Member] | Maximum [Member]
Investment Holdings, Other than Securities [Line Items]
Range of expiration dates	2018-12	[13],[2]
Financial Derivatives - Liabilities [Member] | Short Interest Rate Swaps [Member]
Investment Holdings, Other than Securities [Line Items]
Primary risk exposure	Interest Rates	[10],[2]	Interest Rates	[10],[2]
Notional - liability	(323,800,000)	[10],[2]	(220,000,000)	[10],[2]
Derivative Liabilities	(2,207,000)	[10],[2]	(1,092,000)	[10],[2]
Financial Derivatives - Liabilities [Member] | Short Interest Rate Swaps [Member] | Minimum [Member]
Investment Holdings, Other than Securities [Line Items]
Range of expiration dates	2015-03	[10],[2]	2014-08	[10],[2]
Financial Derivatives - Liabilities [Member] | Short Interest Rate Swaps [Member] | Maximum [Member]
Investment Holdings, Other than Securities [Line Items]
Range of expiration dates	2043-09	[10],[2]	2022-11	[10],[2]
Financial Derivatives - Liabilities [Member] | Short Total Return Swaps [Member]
Investment Holdings, Other than Securities [Line Items]
Primary risk exposure	Equity Market	[2],[7]	Equity Market	[2],[7]
Notional - liability	(10,374,000)	[2],[7]	(18,737,000)	[2],[7]
Range of expiration dates			2013-09	[2],[7]
Derivative Liabilities	(67,000)	[2],[7]	(65,000)	[2],[7]
Financial Derivatives - Liabilities [Member] | Short Total Return Swaps [Member] | Minimum [Member]
Investment Holdings, Other than Securities [Line Items]
Range of expiration dates	2014-09	[2],[7]
Financial Derivatives - Liabilities [Member] | Short Total Return Swaps [Member] | Maximum [Member]
Investment Holdings, Other than Securities [Line Items]
Range of expiration dates	2015-09	[2],[7]
Financial Derivatives - Liabilities [Member] | Swap [Member]
Investment Holdings, Other than Securities [Line Items]
Derivative Liabilities	(42,296,000)	[2]	(15,142,000)	[2]
Investment owned as a percentage of equity	(6.76%)	[2],[3]	(2.99%)	[2],[3]
Net proceeds	(29,746,000)	[2]	(13,171,000)	[2]
Financial Derivatives - Liabilities [Member] | Interest Rate Fixed Swaption [Member]
Investment Holdings, Other than Securities [Line Items]
Primary risk exposure	Interest Rates	[14],[2]
Notional - liability	(4,000,000)	[14],[2]
Range of expiration dates	2014-04	[14],[2]
Derivative Liabilities	(84,000)	[14],[2]
Financial Derivatives - Liabilities [Member] | Long US Treasury Note Futures [Member]
Investment Holdings, Other than Securities [Line Items]
Primary risk exposure	Interest Rates	[15],[2]
Notional - liability	227,200,000	[15],[2]
Range of expiration dates	2014-03	[15],[2]
Derivative Liabilities	(2,370,000)	[15],[2]
Financial Derivatives - Liabilities [Member] | Short Eurodollar Future [Member]
Investment Holdings, Other than Securities [Line Items]
Primary risk exposure	Interest Rates	[16],[2]	Interest Rates	[16],[2]
Notional - liability	(14,000,000)	[16],[2]	(63,000,000)	[16],[2]
Derivative Liabilities	(3,000)	[16],[2]	(70,000)	[16],[2]
Financial Derivatives - Liabilities [Member] | Short Eurodollar Future [Member] | Minimum [Member]
Investment Holdings, Other than Securities [Line Items]
Range of expiration dates	2014-03	[16],[2]	2013-03	[16],[2]
Financial Derivatives - Liabilities [Member] | Short Eurodollar Future [Member] | Maximum [Member]
Investment Holdings, Other than Securities [Line Items]
Range of expiration dates	2015-09	[16],[2]	2013-09	[16],[2]
Financial Derivatives - Liabilities [Member] | Futures [Member]
Investment Holdings, Other than Securities [Line Items]
Derivative Liabilities	(2,373,000)	[2]	(70,000)	[2]
Investment owned as a percentage of equity	(0.38%)	[2],[3]	(0.01%)	[2],[3]
Financial Derivatives - Liabilities [Member] | Put Option [Member]
Investment Holdings, Other than Securities [Line Items]
Derivative Liabilities	(84,000)	[2]
Investment owned as a percentage of equity	(0.01%)	[2],[3]
Financial Derivatives - Liabilities [Member] | Foreign Exchange Forward [Member]
Investment Holdings, Other than Securities [Line Items]
Primary risk exposure	Currency	[2]
Notional - liability	(6,575,000)	[2]
Range of expiration dates	2014-03	[2]
Derivative Liabilities	(38,000)	[2]
Financial Derivatives - Liabilities [Member] | Forwards [Member]
Investment Holdings, Other than Securities [Line Items]
Derivative Liabilities	$ (38,000)	[2]
Investment owned as a percentage of equity	(0.01%)	[2],[3]

[1] In the Company's Consolidated Statement of Assets, Liabilities, and Equity, all balances associated with repurchase agreements, reverse repurchase agreements, and financial derivatives are presented on a gross basis.

[2] See Note 2 and Note 3 in Notes to Consolidated Financial Statements.

[3] Classification percentages are based on Total Equity.

[4] For long credit default swaps on corporate bond indices, the Company sold protection.

[5] For long interest rate swap contracts, a floating rate is being paid and a fixed rate is being received.

[6] For long credit default swaps on asset-backed indices, the Company sold protection.

[7] Notional value represents number of underlying shares or par value times the closing price of the underlying security.

[8] For short credit default swaps on asset-backed securities, the Company purchased protection.

[9] For short credit default swaps on asset-backed indices, the Company purchased protection.

[10] For short interest rate swap contracts, a fixed rate is being paid and a floating rate is being received.

[11] Represents the option on the part of the Company to enter into a credit default swap on a corporate bond index whereby the Company would pay a fixed rate and receive credit protection payments.

[12] Represents the option on the part of the Company to enter into an interest rate swap whereby the Company would pay a fixed rate and receive a floating rate.

[13] For short credit default swaps on corporate bond indices, the Company purchased protection.

[14] Represents the option on the part of a counterparty to enter into an interest rate swap with the Company whereby the Company would receive a fixed rate and pay a floating rate.

[15] Notional value represents the total face amount of U.S. Treasury Notes underlying all contracts held; as of December 31, 2013 1,847 contracts were held.

[16] Every $1,000,000 in notional value represents one contract.