Derivative Instruments (Change in Fair Value of Derivatives Included in the Consolidated Statement of Operations) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	9 Months Ended
Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Derivative Instruments, Gain (Loss) [Line Items]
Change in fair value of derivatives	$ 193,028	$ 161,090	$ 631,030	$ 269,404
Change in fair value of embedded derivatives	36,224	188,201	(8,913)	466,278
Call Options [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Change in fair value of derivatives	129,428	160,735	532,282	280,014
2015 Notes Hedges [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Change in fair value of derivatives	73,504	1,839	101,799	(5,573)
2015 Warrants [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Change in fair value of derivatives	(9,199)	0	(9,199)	0
Interest Rate Swap [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Change in fair value of derivatives	(496)	(1,171)	4,039	(4,319)
Interest Rate Caps [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Change in fair value of derivatives	(209)	(313)	2,109	(718)
2015 Notes Embedded Derivatives [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Change in fair value of embedded derivatives	75,750	1,839	104,045	(5,573)
Fixed Index Annuities [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Change in fair value of embedded derivatives	$ (39,526)	$ 186,362	$ (112,958)	$ 471,851

Net Increase or Decrease in the fair value of the embedded derivative or group of embedded derivatives included in earnings in the period.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 4C

-URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5624171-113959

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 133

-Paragraph 12-16, 44A, 44B

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 133

-Paragraph 44A

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 133

-Paragraph 44A, 44B

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 133

-Paragraph 44B

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details