EMPLOYEE RETIREMENT PLANS (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Closure of manufacturing facility in Sarnia, Ontario
Major assumptions used to determine net periodic benefit (income) cost
Contribution to the pension plan				$ 800,000
Pension Benefits
Components of net periodic benefit cost (income):
Interest cost	1,806,000	1,826,000	3,613,000	3,703,000
Expected return on assets	(2,171,000)	(2,381,000)	(4,342,000)	(4,769,000)
Amortization of:
Prior service cost	1,000	1,000	2,000	2,000
Actuarial loss recognized due to settlement				591,000
Actuarial loss	421,000	247,000	841,000	493,000
Total net periodic benefit cost (income)	57,000	(307,000)	114,000	20,000
Major assumptions used to determine net periodic benefit (income) cost
Discount rate (as a percent)			5.00%	5.55%
Expected long-term rate of return on plan assets (as a percent)			8.25%	8.50%
U.S. defined benefit plan
Major assumptions used to determine net periodic benefit (income) cost
Gross benefits paid				$ 400,000