Pension and Postretirement Benefits Net Periodic Pension Costs (Details) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Pension and Other Postretirement Benefit Expense [Abstract]
Service cost	$ 120	$ 502
Interest expense	1,176	1,462
Expected return on plan assets	(1,403)	(1,554)
Amortization of prior service cost	10	42
Actuarial loss	524	849
Net periodic pension cost	$ 427	$ 1,301