Components of Net Periodic Pension Cost (Narrative) (Details) (USD $)	6 Months Ended	12 Months Ended
	Jun. 30, 2013	Dec. 31, 2012
Defined Benefit Plan Disclosure [Line Items]
Defined Contribution Plan, Employer Discretionary Contribution Amount	$ 3,500,000
Minimum amount to be funded as required by the Pension Relief Act Fifteen Year amortization of the Shortfall Amortization Base	$ 450,000	$ 300,000
Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Funded Percentage	85.00%
Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Funded Percentage	115.00%