Note 6 - Fair Value - Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - Fair Value, Measurements, Recurring [Member] - USD ($) $ in Thousands		Dec. 31, 2018	Mar. 31, 2018
Assets held in the non-qualified deferred compensation program	[1]	$ 7,133	$ 6,649
Foreign currency derivatives	[2]	697	257
Assets measured at fair value, Total		7,830	6,906
Obligation related to assets held in the non-qualified deferred compensation program	[1]	7,133	6,649
Foreign currency derivatives liabilities	[2]	679	514
Liabilities measured at fair value, Total		7,812	7,163
Fair Value, Inputs, Level 1 [Member]
Assets held in the non-qualified deferred compensation program	[1]	5,342	5,959
Foreign currency derivatives	[2]
Assets measured at fair value, Total		5,342	5,959
Obligation related to assets held in the non-qualified deferred compensation program	[1]	5,342	5,959
Foreign currency derivatives liabilities	[2]
Liabilities measured at fair value, Total		5,342	5,959
Fair Value, Inputs, Level 2 [Member]
Assets held in the non-qualified deferred compensation program	[1]	1,791	690
Foreign currency derivatives	[2]	697	257
Assets measured at fair value, Total		2,488	947
Obligation related to assets held in the non-qualified deferred compensation program	[1]	1,791	690
Foreign currency derivatives liabilities	[2]	679	514
Liabilities measured at fair value, Total		2,470	1,204
Fair Value, Inputs, Level 3 [Member]
Assets held in the non-qualified deferred compensation program	[1]
Foreign currency derivatives	[2]
Assets measured at fair value, Total
Obligation related to assets held in the non-qualified deferred compensation program	[1]
Foreign currency derivatives liabilities	[2]
Liabilities measured at fair value, Total

[1] The market value of the assets held in the trust for the non-qualified deferred compensation program is included as an asset and as a liability as the trust's assets are both assets of the Company and also a liability as they are available to general creditors in certain circumstances.

[2] Foreign currency derivatives in the form of forward contracts are included in prepaid and other assets or accrued expenses in the consolidated balance sheets. Unrealized gains and losses on derivatives designated as cash flow hedges are recorded in other comprehensive income (loss). Realized gains and losses on derivatives designated as cash flow hedges and gains and losses on derivatives not designated as hedges are recorded in other income.