Condensed Consolidated Statement of Comprehensive Income (Loss) - USD ($) shares in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Statement of Comprehensive Income [Abstract]
Net Sales		$ 246,152,000	$ 233,517,000	$ 483,212,000	$ 465,240,000
Cost of products sold		178,806,000	168,495,000	349,349,000	335,073,000
Gross Profit		67,346,000	65,022,000	133,863,000	130,167,000
Selling, general and administrative expenses		73,763,000	75,721,000	145,027,000	148,234,000
Charges related to restructuring activities		344,000	4,987,000	745,000	8,270,000
Operating Income (Loss)		(6,761,000)	(15,686,000)	(11,909,000)	(26,337,000)
Loss (gain) on Convertible Debt Derivatives		(21,000)	1,051,000	(124,000)	150,000
Interest expense		6,964,000	4,645,000	13,926,000	9,163,000
Interest income		(136,000)	(49,000)	(385,000)	(137,000)
Loss Before Income Taxes		(13,568,000)	(21,333,000)	(25,326,000)	(35,513,000)
Income tax provision		2,975,000	2,175,000	5,325,000	4,775,000
Net Loss		$ (16,543,000)	$ (23,508,000)	$ (30,651,000)	$ (40,288,000)
Dividends Declared per Common Share		$ 0.0125	$ 0.0125	$ 0.0250	$ 0.0250
Net Earnings (Loss) per Share—Basic
Net Loss per Share—Basic		$ (0.50)	$ (0.72)	$ (0.93)	$ (1.23)
Weighted Average Shares Outstanding—Basic		33,169	32,833	33,040	32,654
Net Earnings (Loss) per Share—Assuming Dilution
Net Loss per Share—Assuming Dilution	[1]	$ (0.50)	$ (0.72)	$ (0.93)	$ (1.23)
Weighted Average Shares Outstanding—Assuming Dilution		33,996	33,193	33,867	32,947
Other comprehensive income (loss):
Foreign currency translation adjustments		$ (23,438,000)	$ 26,311,000	$ (11,622,000)	$ 27,260,000
Defined Benefit Plans:
Amortization of prior service costs and unrecognized gains (loss)		290,000	(426,000)	243,000	(721,000)
Deferred tax adjustment resulting from defined benefit plan activity		33,000	15,000	(49,000)	12,000
Valuation reserve (reversal) associated with defined benefit plan activity		(33,000)	(15,000)	49,000	(12,000)
Current period unrealized gain (loss) on cash flow hedges		1,966,000	(1,907,000)	1,719,000	(1,276,000)
Deferred tax benefit (loss) related to unrealized gain (loss) on cash flow hedges		(261,000)	271,000	(151,000)	105,000
Other Comprehensive Income (Loss)		(21,443,000)	24,249,000	(9,811,000)	25,368,000
Comprehensive Income (Loss)		$ (37,986,000)	$ 741,000	$ (40,462,000)	$ (14,920,000)
Net Sales, as a Percent of Net Sales		100.00%	100.00%	100.00%	100.00%
Cost of Products Sold, as a Percent of Net Sales		72.60%	72.20%	72.30%	72.00%
Gross Profit, as a Percent of Net Sales		27.40%	27.80%	27.70%	28.00%
Selling, general and administrative expenses, as a Percent of Net Sales		30.00%	32.40%	30.00%	31.90%
Charges related to restructuring activities, as a Percent of Net Sales		0.10%	2.10%	0.20%	1.80%
Operating Gain (Loss), as a Percent of Net Sales		(2.70%)	(6.70%)	(2.50%)	(5.70%)
Net loss (gain) on convertible debt derivatives, as a Percent of Net Sales		0.00%	0.50%	0.00%	0.00%
Interest expense, as a Percent of Net Sales		2.80%	2.00%	2.90%	2.00%
Interest income, as a Percent of Net Sales		(0.10%)	0.00%	(0.10%)	0.00%
Gain (loss) Before Income Taxes, as a Percent of Net Sales		(5.50%)	(9.10%)	(5.20%)	(7.60%)
Income Tax Provision, as a Percent of Net Sales		1.20%	0.90%	1.10%	1.00%
Net Gain (Loss), as a percent of Net Sales		(6.70%)	(10.10%)	(6.30%)	(8.70%)

[1] Net loss per common share assuming dilution calculated utilizing weighted average shares outstanding-basic for the periods in which there was a net loss.