Pension and Other Benefits (Details) (1) (USD $)	3 Months Ended		9 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012	Dec. 31, 2011
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Defined Benefit Plan, Curtailments				$ 1,172,000
Service costs			1,869,000	2,537,000
Interest cost			7,443,000	7,521,000
Pension Plans, Defined Benefit [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Defined Benefit Plan, Curtailments	0	0
Service costs	623,000	846,000
Interest cost	2,481,000	2,507,000
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Interest cost	$ 78,000	$ 120,000	$ 234,000	$ 359,000