Segments (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended			9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2011	Sep. 30, 2014 segment	Sep. 30, 2013
Segment Reporting Information [Line Items]
Number of reportable segments				3
Net Sales:
Net sales	$ 215,957	$ 204,386		$ 621,074	$ 597,766
Segment EBIT:
Segment EBIT	29,325	21,325		83,946	80,812
Reconciliation of Segment EBIT to Net Income (Loss):
Retained corporate costs	(7,243)	(4,448)		(21,995)	(16,462)
Loss on redemption of debt (note 4)	0	0		(47,191)	(2,518)
Pension settlement (note 7)	0	(760)		0	(1,475)
Furnace malfunction (note 14)	0	(2,437)		(5,882)	(2,437)
Restructuring charges (note 5)	0	(390)		(985)	(6,318)
Abandoned property (note 14)	0	0	(2,700)	0	(1,781)
Interest expense	(4,797)	(7,706)		(17,984)	(24,267)
Income taxes	(3,527)	(835)		(4,703)	(6,380)
Net income (loss)	13,758	4,749		(14,794)	19,174
Depreciation & Amortization:
Depreciation and amortization	9,569	11,773		30,837	34,170
Capital Expenditures:
Capital Expenditures	16,693	10,381		38,528	30,152
Americas [Member]
Net Sales:
Net sales	149,366	141,390		425,741	406,740
Segment EBIT:
Segment EBIT	25,489	21,224		73,464	73,149
Depreciation & Amortization:
Depreciation and amortization	5,153	5,975		16,963	19,824
Capital Expenditures:
Capital Expenditures	15,196	4,231		31,991	18,140
EMEA [Member]
Net Sales:
Net sales	37,684	35,491		111,413	107,714
Segment EBIT:
Segment EBIT	909	(135)		3,072	(806)
Depreciation & Amortization:
Depreciation and amortization	2,624	2,930		7,988	7,923
Capital Expenditures:
Capital Expenditures	1,070	1,307		4,348	4,348
U.S. Sourcing [Member]
Net Sales:
Net sales	20,574	19,868		59,704	58,548
Segment EBIT:
Segment EBIT	2,206	2,067		5,375	7,186
Depreciation & Amortization:
Depreciation and amortization	6	9		20	27
Capital Expenditures:
Capital Expenditures	0	0		0	32
Other Segments [Member]
Net Sales:
Net sales	8,333	7,637		24,216	24,764
Segment EBIT:
Segment EBIT	721	(1,831)		2,035	1,283
Depreciation & Amortization:
Depreciation and amortization	1,444	2,578		4,716	5,350
Capital Expenditures:
Capital Expenditures	359	3,955		1,251	5,578
Corporate [Member]
Depreciation & Amortization:
Depreciation and amortization	342	281		1,150	1,046
Capital Expenditures:
Capital Expenditures	$ 68	$ 888		$ 938	$ 2,054