Statement of Consolidated Comprehensive Income (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended	6 Months Ended
Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Statement of Consolidated Comprehensive Income (Unaudited) [Abstract]
Net income	$ 20,624	$ 12,826	$ 43,490	$ 12,332
Other comprehensive income, net of tax
Unrealized gains on securities	5,076	22,477	2,123	19,960
Pension and other postretirement benefits	394	391	1,472	782
Other comprehensive income	5,470	22,868	3,595	20,742
Comprehensive income	$ 26,094	$ 35,694	$ 47,085	$ 33,074

The change in equity [net assets] of a business enterprise during a period from transactions and other events and circumstances from non-owner sources which are attributable to the economic entity, including both controlling (parent) and noncontrolling interests. It includes all changes in equity during a period except those resulting from investments by owners and distributions to owners, including any and all transactions which are directly or indirectly attributable to that ownership interest in subsidiary equity which is not attributable to the parent.

+ References+ Details

Gross appreciation or the gross loss in value of the total unsold securities. While for technical reasons this element has no balance attribute, the default assumption is a credit balance consistent with its label.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 220

-SubTopic 10

-Section 55

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+ Details

- Definition

The increase (decrease) in accumulated comprehensive income during the period related to pension and other postretirement benefit plans, after tax. While for technical reasons this element has no balance attribute, the default assumption is a credit balance consistent with its label.

+ References+ Details

- Definition

This element represents Other Comprehensive Income or Loss, Net of Tax, for the period. Includes deferred gains or losses on qualifying hedges, unrealized holding gains or losses on available-for-sale securities, minimum pension liability, and cumulative translation adjustment. While for technical reasons this element has no balance attribute, the default assumption is a credit balance consistent with its label.

+ References

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-Publisher AICPA

-Name Accounting Principles Board Opinion (APB)

-Number 12

-Paragraph 10

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

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+ Details

- Definition

The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest.

+ References

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+ Details