Retirement Benefits (Schedule of Defined Benefit Plan Amounts Recognized in Other Comprehensive Income (Loss)) (Details) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Retirement Benefits [Abstract]
Net actuarial loss	$ 2,243,000	$ 3,264,000
Amortization of:
Net Actuarial loss	(1,330,000)	(424,000)
Prior service costs	(3,023,000)	(3,023,000)
Total recognized in other comprehensive income (loss)	(2,110,000)	(183,000)
Estimated prior service cost that will be amortized from accumulated other comprehensive income (loss) into periodic benefit cost during 2012	2,197,000
Estimated net actuarial loss that will be amortized from accumulated other comprehensive income (loss) into periodic benefit cost during 2012	$ 3,023,000