Retirement Plans (Schedule of Costs of Retirement Plans) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Defined Benefit Plan Disclosure [Line Items]
Pension Expense	$ 715	$ 644	$ 2,017	$ 1,821
Salaried Benefit Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension Expense	599	541	1,674	1,519
Union Benefit Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension Expense	23	16	59	45
Montreal Benefit Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension Expense	30	26	89	75
United Kingdom Benefit Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension Expense	29	34	84	94
Kelsan Benefit Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension Expense	$ 34	$ 27	$ 111	$ 88