Junior Subordinated Debt Securities Payable (Narrative) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2012
Debt Instrument [Line Items]
Junior subordinated debt securities, maturity date	Mar. 29, 2034
Net assets of Holdings' consolidated subsidiaries, subject to regulatory restrictions	$ 2,272,346
Net assets of consolidated subsidiaries	$ 3,068,916
Junior Subordinated Debt [Member]
Debt Instrument [Line Items]
Percentage of principal redeemable before maturity	100.00%
Debt securities, Trust may become subject to tax within number of days of redemption period	90 days

Debt Securities Maturity Percentage In Date Of Redemption

No definition available.

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- Definition

Minimum Days For Debt Securities Become Subject To Tax

+ References

No definition available.

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- Definition

Amount of restricted net assets of consolidated and unconsolidated subsidiaries as of the end of the most recently completed fiscal year.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.4-08.(e)(3)(ii))

-URI http://asc.fasb.org/extlink&oid=6881521&loc=d3e23780-122690

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 08

-Paragraph e

-Subparagraph 3

-Article 4

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- Definition

Date of maturity of a debt security categorized as held-to-maturity, in CCYY-MM-DD format.

+ References

No definition available.

+ Details

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- Definition

The net amount of all regulatory assets less all regulatory liabilities as of the end of the period.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 980

-SubTopic 340

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6499975&loc=d3e44250-110382

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