Fair Value Measurements (Reconciliation For All Assets And Liabilities Of The Company Measured At Fair Value On A Recurring Basis Using Significant Unobservable Inputs (Level 3)) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2013	Mar. 31, 2012
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance, January 1	$ 1,203	$ 52,623
Purchases	0	0
Issuances	0	0
Principal prepayments and settlements	0	(3,267)
Sales	0	0
Total gains or (losses) (realized/unrealized), Included in earnings	(41)	2,885
Total gains or (losses) (realized/unrealized), Included in other comprehensive income	0	0
Transfers in and out of Level 3	0	0
Ending balance	$ 1,162	$ 52,241

Fair Value Measurements (Reconciliation For All Assets And Liabilities Of The Company Measured At Fair Value On A Recurring Basis Using Significant Unobservable Inputs (Level 3)) (Details) (USD $)
In Thousands, unless otherwise specified

3 Months Ended

Mar. 31, 2013

Mar. 31, 2012

Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]

Beginning balance, January 1

$ 1,203

$ 52,623

Purchases

Issuances

Principal prepayments and settlements

(3,267)

Sales

Total gains or (losses) (realized/unrealized), Included in earnings

(41)

2,885

Total gains or (losses) (realized/unrealized), Included in other comprehensive income

Transfers in and out of Level 3

Ending balance

$ 1,162

$ 52,241

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Amount of gain (loss) recognized in earnings, arising from assets measured at fair value on a recurring basis using unobservable inputs (level 3).

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Amount of gain (loss) recognized in other comprehensive income, arising from assets measured at fair value on a recurring basis using unobservable inputs (level 3).

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Issues that have taken place during the period in relation to assets measured at fair value and categorized within Level 3 of the fair value hierarchy.

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Purchases that have taken place during the period in relation to assets measured at fair value and categorized within Level 3 of the fair value hierarchy.

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- Definition

Sales that have taken place during the period in relation to assets measured at fair value and categorized within Level 3 of the fair value hierarchy.

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Settlements that have taken place during the period in relation to assets measured at fair value and categorized within Level 3 of the fair value hierarchy.

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- Definition

Transfers out of assets measured at fair value and categorized within Level 3 of the fair value hierarchy that have taken place during the period.

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- Definition

This element represents an asset measured at fair value using significant unobservable inputs (Level 3) which is required for reconciliation purposes of beginning and ending balances.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=7578670&loc=d3e19207-110258

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 157

-Paragraph 32

-Subparagraph c

-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.

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