Pension and Other Post-retirement Benefit Plans (Details 2) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2013
Target allocation and weighted-average asset allocations
Target Allocation (as a percent)	100.00%
Plan Assets (as a percent)	100.00%
Estimated future pension benefit payments
2015	$ 1,465
2016	1,458
2017	1,472
2018	1,596
2019	1,683
2021- 2025	9,963
Pension
Other changes in plan assets and benefit obligations recognized in Accumulated other comprehensive income
Current year actuarial (gain) loss	12,397	(190)	3,669
Foreign currency exchange rate changes	0	0	(238)
Amortization of actuarial gain (loss)	(258)	(286)	(4,582)
Current year prior service cost	1,006	285	0
Amortization of prior service cost	(17)	(4)	(101)
Total recognized in other comprehensive income	13,128	(195)	(1,252)
Total recognized in net periodic benefit cost and other comprehensive income (loss)	16,028	2,683	2,408
Estimated future pension benefit payments
2015	1,367
2016	1,363
2017	1,381
2018	1,510
2019	1,603
2021- 2025	9,654
Other Benefits
Other changes in plan assets and benefit obligations recognized in Accumulated other comprehensive income
Current year actuarial (gain) loss	118	95	(145)
Foreign currency exchange rate changes	0	0	0
Amortization of actuarial gain (loss)	187	259	322
Current year prior service cost	0	0	0
Amortization of prior service cost	0	0	0
Total recognized in other comprehensive income	305	354	177
Total recognized in net periodic benefit cost and other comprehensive income (loss)	147	118	(118)
Estimated future pension benefit payments
2015	98
2016	95
2017	91
2018	86
2019	80
2021- 2025	$ 309
Insurance
Target allocation and weighted-average asset allocations
Target Allocation (as a percent)	10.00%
Plan Assets (as a percent)	6.00%
International equities
Target allocation and weighted-average asset allocations
Target Allocation (as a percent)	30.00%
Plan Assets (as a percent)	35.00%
International bonds
Target allocation and weighted-average asset allocations
Target Allocation (as a percent)	50.00%
Plan Assets (as a percent)	58.00%
Other
Target allocation and weighted-average asset allocations
Target Allocation (as a percent)	10.00%
Plan Assets (as a percent)	1.00%