Retirement Plans (Schedule of Costs of Retirement Plans) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Defined Benefit Plan Disclosure [Line Items]
Pension Expense	$ 718	$ 538	$ 1,277	$ 1,151
Salaried Benefit Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension Expense	620	450	1,075	978
Union Benefit Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension Expense	19	15	36	28
Montreal Benefit Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension Expense	32	25	59	48
United Kingdom Benefit Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension Expense	16	18	30	36
Kelsan Benefit Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension Expense	$ 31	$ 30	$ 77	$ 61