Condensed Consolidated Statements of Operations and Retained Earnings - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Revenues [Abstract]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 139,070	$ 212,712
Cost of Goods and Services Sold	94,273	137,100
Gross Profit	44,797	75,612
Operating Expenses [Abstract]
Selling expenses	18,695	22,755
General and administrative expenses	18,429	19,600
Research and Development Expense	2,769	2,792
Impairment of Long-Lived Assets to be Disposed of	0	169
Amortization of intangibles	3,115	3,253
Operating Expenses	43,008	48,569
Income from operations	1,789	27,043
Other Income & Expenses [Abstract]
Interest and debt expense	3,188	3,852
Investment (income) loss	(577)	(302)
Foreign currency exchange (gain) loss	84	(410)
Other (income) expense, net	3,026	162
Income Tax Expense Benefit [Abstract]
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest	(3,932)	23,741
Income tax expense (benefit)	(963)	5,162
Net income (loss)	(2,969)	18,579
Retained Earnings Accumulated Deficit [Abstract]
Retained earnings - beginning of period	290,441	$ 236,459
Retained earnings - end of period	$ 287,472
Weighted Average Number Of Shares Outstanding Basic [Abstract]
Average basic shares outstanding	23,802	23,431
Weighted Average Number Of Shares Outstanding [Abstract]
Average diluted shares outstanding	23,802	23,777
Earnings Per Share Basic [Abstract]
Basic income (loss) per share:	$ (0.12)	$ 0.79
Earnings Per Share Diluted [Abstract]
Diluted income (loss) per share:	(0.12)	$ 0.78
Common Stock, Dividends, Per Share, Declared	$ 0.06