EMPLOYEE RETIREMENT PLANS (Details) (USD $)	12 Months Ended	3 Months Ended
	Dec. 31, 2011 Closure of manufacturing facility in Sarnia, Ontario	Mar. 31, 2012 Pension Benefits	Mar. 31, 2011 Pension Benefits	Mar. 31, 2012 U.S. defined benefit plan	Mar. 31, 2011 U.S. defined benefit plan
Components of net periodic benefit cost:
Interest cost		$ 1,806,000	$ 1,877,000
Expected return on assets		(2,171,000)	(2,389,000)
Amortization of:
Prior service cost		1,000	1,000
Actuarial loss recognized due to settlement			591,000
Actuarial loss		421,000	247,000
Total net periodic benefit cost (income)		57,000	327,000
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%
Contribution to the pension plan	800,000
Gross benefits paid				$ 400,000	$ 400,000