Restructuring And Impairment Costs (Narrative) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		12 Months Ended
	Jun. 30, 2011 Termination Of Business Arrangements With Supplier And Processor [Member]	Dec. 31, 2011 Canadian Operations [Member]	Mar. 31, 2011 Canadian Operations [Member]	Mar. 31, 2012 Total Costs Cummulative [Member] employees
Restructuring Cost and Reserve [Line Items]
Impairment charge - property, plant, and equipment		$ 5,600		$ 5,632
Employee termination benefits			2,400	19,719
Pension curtailment and settlement costs			4,100	4,081
Other restructuring costs	$ 3,100			$ 3,733
Total employees receiving employee termination benefits				350