Other Postretirement Benefit Plans (Details Textual)	6 Months Ended
	Jun. 30, 2012 Age
Other Postretirement Benefit Plans (Textual) [Abstract]
Minimum year of service to qualify for postretirement medical benefits	20 years
Minimum age to qualify for postretirement medical benefits	60
Condition to qualify for postretirement medical benefits	Employees who had worked 20 years and attained a minimum age of 60 by September 1, 2000