XML 18 R70.htm IDEA: XBRL DOCUMENT v2.4.0.6
Pension And Other Postretirement Benefit Plans (Components Of Company's Net Periodic Benefit Cost) (Details) (USD $)
In Thousands, unless otherwise specified
 12 Months Ended
Mar. 31, 2012
Mar. 31, 2011
Mar. 31, 2010
Pension Benefits [Member]
      
Defined Benefit Plan Disclosure [Line Items]      
Service cost $ 4,614 $ 4,835 $ 3,815
Interest cost 13,959 14,168 14,899
Expected return on plan assets (14,958) (14,938) (13,687)
Curtailment loss 0 966 0
Settlement cost 0 3,119 4,640
Net amortization and deferral 6,309 3,937 1,387
Net periodic benefit cost 9,924 12,087 11,054
Other Postretirement Benefits [Member]
      
Defined Benefit Plan Disclosure [Line Items]      
Service cost 591 787 581
Interest cost 2,636 2,534 2,789
Expected return on plan assets (134) (144) (152)
Curtailment loss 0 0 0
Settlement cost 0 0 0
Net amortization and deferral (335) (253) (1,083)
Net periodic benefit cost $ 2,758 $ 2,924 $ 2,135