Pension and Postretirement Benefit Costs Details Textuals (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Mar. 31, 2012
Defined Benefit Plan Disclosure [Line Items]
Minimum contribution in 2012 to unqualified plan	$ 2.0
funding threshhold		80.00%
Minimum contributions in 2012 on qualified plan	$ 5.0