Segments (Details) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2015 USD ($)	Sep. 30, 2014 USD ($)	Sep. 30, 2015 USD ($) segment	Sep. 30, 2014 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment				3
Net Sales:
Net sales		$ 201,784	$ 215,957	$ 603,200	$ 621,074
Segment EBIT:
Segment EBIT		28,281	29,325	80,513	83,946
Reconciliation of Segment EBIT to Net Income (Loss):
Retained corporate costs		(7,969)	(7,243)	(26,626)	(22,065)
Loss on redemption of debt (note 4)		0	0	0	(47,191)
Furnace malfunction (note 14)		0	0	0	(5,882)
Environmental obligation (note 14)		100	0	(123)	0
Reorganization charges (1)	[1]	(1,176)	0	(4,191)	0
Restructuring charges (note 5)		0	0	0	(985)
Derivatives (2)	[2]	(42)	0	125	70
Executive retirement		0	0	(235)	0
Interest expense		(4,701)	(4,797)	(13,762)	(17,984)
Income taxes		2,226	(3,527)	(1,476)	(4,703)
Net income (loss)		16,719	13,758	34,225	(14,794)
Depreciation & Amortization:
Depreciation and amortization		10,633	9,569	31,286	30,837
Capital Expenditures:
Capital Expenditures		8,244	16,693	41,480	38,528
Americas [Member]
Net Sales:
Net sales		139,477	149,366	417,340	425,741
Segment EBIT:
Segment EBIT		23,908	25,489	68,788	73,464
Depreciation & Amortization:
Depreciation and amortization		6,666	5,153	19,148	16,963
Capital Expenditures:
Capital Expenditures		5,826	15,196	34,604	31,991
EMEA [Member]
Net Sales:
Net sales		30,572	37,684	91,207	111,413
Segment EBIT:
Segment EBIT		254	909	1,274	3,072
Depreciation & Amortization:
Depreciation and amortization		2,131	2,624	6,445	7,988
Capital Expenditures:
Capital Expenditures		1,726	1,070	4,501	4,348
U.S. Sourcing [Member]
Net Sales:
Net sales		23,495	20,574	67,452	59,704
Segment EBIT:
Segment EBIT		3,214	2,206	6,600	5,375
Depreciation & Amortization:
Depreciation and amortization		6	6	18	20
Capital Expenditures:
Capital Expenditures		0	0	0	0
Other Segments [Member]
Net Sales:
Net sales		8,240	8,333	27,201	24,216
Segment EBIT:
Segment EBIT		905	721	3,851	2,035
Depreciation & Amortization:
Depreciation and amortization		1,462	1,444	4,434	4,716
Capital Expenditures:
Capital Expenditures		451	359	991	1,251
Corporate [Member]
Depreciation & Amortization:
Depreciation and amortization		368	342	1,241	1,150
Capital Expenditures:
Capital Expenditures		$ 241	$ 68	$ 1,384	$ 938

[1] Management reorganization to support our growth strategy.

[2] Derivatives relate to hedge ineffectiveness on our natural gas contracts and interest rate swap, as well as, mark-to-market adjustments on our natural gas contracts that have been de-designated and those for which we did not elect hedge accounting.