Income Taxes Deferred Taxes (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Mar. 31, 2015
Deferred tax liabilities:
Unremitted earnings of foreign subsidiaries	$ 27,641	$ 22,043
Intangible assets	9,334	6,415
Fixed assets	11,435	3,488
Total deferred tax liabilities	48,410	31,946
Deferred tax assets:
Reserves and accruals	(23,870)	(29,610)
Tax credits	(8,191)	(55,744)
Tax loss carryforwards	(104,337)	(105,345)
Derivative transactions	(892)	(567)
Postretirement and other benefits	(30,635)	(34,388)
Unrealized exchange loss	(12,645)	(10,057)
Other	(8,207)	(4,926)
Gross deferred tax assets	(188,777)	(240,637)
Valuation allowance	118,518	169,804
Total deferred tax assets	(70,259)	(70,833)
Net deferred tax asset	$ (21,849)	$ (38,887)