Other Comprehensive Income (Loss) Reclassifications from Accumulated Other Comprehensive Income (Loss) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2014	Dec. 31, 2013
Statement of Comprehensive Income [Abstract]
Reclassification adjustment for sales of available-for-sale securities, net of tax	$ 3	$ 21	$ 8	$ 507
Other Comprehensive (Income) Loss, Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, for Net (Gain) Loss, Net of Tax	0	(1,148)	0	(1,148)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	$ 3	$ (1,127)	$ 8	$ (641)