Deferred Policy Acquisition Costs and Present Value of Future Profits (Details Textual) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2012 USD ($)	Dec. 31, 2012 JPY (¥)
Deferred Policy Acquisition Costs and Present Value of Future Profits [Abstract]
Estimated future net amortization expense of present value of future profits in 2013	$ 22
Estimated future net amortization expense of present value of future profits in 2014	6
Estimated future net amortization expense of present value of future profits in 2015	6
Estimated future net amortization expense of present value of future profits in 2016	6
Estimated future net amortization expense of present value of future profits in 2017		¥ 5

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Expected amortization expense in the fifth year after the balance sheet date of the present value of the future profits of long-duration contracts acquired in a purchase of an insurance enterprise.

+ References

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

-Publisher FASB

-Name Emerging Issues Task Force (EITF)

-Number 92-9

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 20

-Section S99

-Paragraph 2

-Subparagraph (3)

-URI http://asc.fasb.org/extlink&oid=6784649&loc=d3e569990-122904

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- Definition

Expected amortization expense in the fourth year after the balance sheet date of the present value of the future profits of long-duration contracts acquired in a purchase of an insurance enterprise.

+ References

+ Details

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- Definition

Expected amortization expense in the first year after the balance sheet date of the present value of the future profits of long-duration contracts acquired in a purchase of an insurance enterprise.

+ References

+ Details

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- Definition

Expected amortization expense in the third year after the balance sheet date of the present value of the future profits of long-duration contracts acquired in a purchase of an insurance enterprise.

+ References

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- Definition

Expected amortization expense in the second year after the balance sheet date of the present value of the future profits of long-duration contracts acquired in a purchase of an insurance enterprise.

+ References

+ Details

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