Employee Benefits Defined Benefit Plans (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, before Tax	$ 260	$ 492
Martin Currie [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Assets for Plan Benefits, Defined Benefit Plan	$ 41,189	$ 40,554
Equity [Member] | Fair Value, Inputs, Level 1 [Member] | Martin Currie [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage	64.00%	64.00%
Equity Funds [Member] | Fair Value, Inputs, Level 1 [Member] | Martin Currie [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	60.00%
Bonds [Member] | Fair Value, Inputs, Level 1 [Member] | Martin Currie [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage	36.00%	35.00%
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	40.00%