Condensed Consolidated Statements of Operations and Comprehensive Income (Loss) (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Income Statement [Abstract]
Net sales	$ 225,875	$ 214,272	$ 452,189	$ 426,498
Cost of products sold (exclusive of depreciation and amortization shown separately below)	166,040	156,794	332,994	316,548
Selling, general and administrative expense	23,036	20,993	44,530	41,795
Depreciation and amortization	15,900	15,136	31,468	32,484
Restructuring and integration expense	306	4,047	446	6,585
Income from operations	20,593	17,302	42,751	29,086
Interest expense	12,409	16,631	27,365	33,053
Loss on extinguishment of debt and write-off of unamortized debt issuance costs	39,639		39,639
Derivative losses on change in interest rate swap fair value	101		13
Other (income) expense, net	645	(824)	(79)	(1,953)
Income (loss) before provision (benefit) for income taxes and share of net income from joint venture	(32,201)	1,495	(24,187)	(2,014)
Provision (benefit) for income taxes	(9,428)	719	(7,128)	(31)
Share of net income from joint venture	1,244	1,343	2,937	2,743
Net income (loss)	(21,529)	2,119	(14,122)	760
Other comprehensive income (loss):
Change in fair value of interest rate swap		416		(219)
Foreign currency translation gain (loss)	9,240	(5,071)	14,244	2,152
Other comprehensive income (loss):	9,240	(4,655)	14,244	1,933
Comprehensive income (loss)	$ (12,289)	$ (2,536)	$ 122	$ 2,693
Basic net income (loss) per share:
Net income (loss)	$ (0.78)	$ 0.08	$ (0.52)	$ 0.03
Weighted average shares outstanding	27,468	27,024	27,358	26,923
Diluted net income (loss) per share:
Net income (loss)	$ (0.78)	$ 0.08	$ (0.52)	$ 0.03
Weighted average shares outstanding	27,468	27,187	27,358	27,050
Cash dividends per common share	$ 0.07	$ 0.07	$ 0.14	$ 0.14