EMPLOYEE BENEFIT PLANS (Details) (PLC, USD $)	3 Months Ended		1 Months Ended	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Apr. 30, 2013 2012 plan year	Mar. 31, 2013 2012 plan year
EMPLOYEE BENEFIT PLANS
Service cost - benefits earned during the period	$ 2,708,000	$ 2,561,000
Interest cost on projected benefit obligation	2,553,000	2,604,000
Expected return on plan assets	(2,759,000)	(2,673,000)
Amortization of prior service cost/(credit)	(95,000)	(95,000)
Amortization of actuarial losses	2,729,000	2,175,000
Total benefit cost	5,136,000	4,572,000
Contribution made by the company to its defined benefit pension plan			$ 2,300,000
Adjusted funding target percentage to be maintained, minimum				80.00%
Age of eligibility for prescription drug benefit	65 years