Pension and Other Post-Retirement Benefit Plans (Fair Value Measurements Using Significant Level 3 Unobservable Inputs) (Details) (Level 3 [Member], USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011
Schedule of Level Three Defined Benefit Plan Assets [Roll Forward]
Plan assets, beginning balance	$ 40,316	$ 37,724
Unrealized gains	6,236	3,056
Purchases & settlements	(2,402)	(464)
Plan assets, ending balance	44,150	40,316
Hedge Funds & Private Equity [Member]
Schedule of Level Three Defined Benefit Plan Assets [Roll Forward]
Plan assets, beginning balance	25,759	25,510
Unrealized gains	3,612	713
Purchases & settlements	(2,402)	(464)
Plan assets, ending balance	26,969	25,759
Real Estate Investments [Member]
Schedule of Level Three Defined Benefit Plan Assets [Roll Forward]
Plan assets, beginning balance	14,557	12,214
Unrealized gains	2,624	2,343
Purchases & settlements	0	0
Plan assets, ending balance	$ 17,181	$ 14,557

The amounts in accumulated other comprehensive income related to gains and losses that are not recognized immediately and are expected to be recognized as components of net periodic benefit cost over the next fiscal year that follows the most recent annual statement of financial position presented.

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Assets, usually stocks, bonds, and other investments, that have been segregated and restricted (usually in a trust) to provide benefits, at their fair value as of the measurement date. Plan assets include amounts contributed by the employer (and by employees for a contributory plan) and amounts earned from investing the contributions, less benefits paid. If a plan has liabilities other than for benefits, those non-benefit obligations may be considered as reductions of plan assets.

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