Income Taxes Deferred Taxes (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Mar. 31, 2016
Deferred tax liabilities:
Unremitted earnings of foreign subsidiaries	$ 30,581	$ 27,641
Intangible assets	8,397	9,334
Fixed assets	7,242	11,435
Total deferred tax liabilities	46,220	48,410
Deferred tax assets:
Reserves and accruals	(24,308)	(23,870)
Tax credits	(7,286)	(8,191)
Tax loss carryforwards	(125,601)	(104,337)
Derivative transactions	(669)	(892)
Postretirement and other benefits	(28,512)	(30,635)
Unrealized exchange loss	(4,046)	(12,645)
Other	(8,471)	(8,207)
Gross deferred tax assets	(198,893)	(188,777)
Valuation allowance	131,774	118,518
Total deferred tax assets	(67,119)	(70,259)
Net deferred tax asset	$ (20,899)	$ (21,849)