Condensed Consolidated Statements of Operations and Retained Earnings - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Revenues [Abstract]
Net sales	$ 149,013	$ 136,236
Cost of products sold	100,966	92,652
Gross profit	48,047	43,584
Operating Expenses [Abstract]
Selling expenses	18,814	16,598
General and administrative expenses	16,282	15,102
Amortization of intangibles	1,750	593
Total operating expenses	36,846	32,293
Income from operations	11,201	11,291
Other Income & Expenses [Abstract]
Interest and debt expense	2,574	1,156
Investment (income) loss	(217)	(128)
Foreign currency exchange (gain) loss	(563)	(185)
Other (income) expense, net	(80)	(5)
Income before income tax expense	9,487	10,453
Income Tax Expense Benefit [Abstract]
Income tax expense	3,086	3,542
Net income	6,401	6,911
Retained Earnings Accumulated Deficit [Abstract]
Retained earnings - beginning of period	174,173	157,811
Retained earnings - end of period	$ 180,574	$ 164,722
Weighted Average Number Of Shares Outstanding Basic [Abstract]
Average basic shares outstanding	20,135,000	20,022,000
Weighted Average Number Of Shares Outstanding [Abstract]
Average diluted shares outstanding	20,266,000	20,229,000
Earnings Per Share Basic [Abstract]
Net income	$ 0.32	$ 0.35
Earnings Per Share Diluted [Abstract]
Net income	0.32	$ 0.34
Common Stock, Dividends, Per Share, Declared	$ 0.04