Summary of Significant Accounting Policies (Details 6) (USD $) In Thousands, unless otherwise specified	3 Months Ended								6 Months Ended	9 Months Ended	12 Months Ended
	Dec. 31, 2013	Sep. 29, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Jun. 30, 2013	Sep. 29, 2013	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Consolidated Statements of Operations
Net sales	$ 69,792	$ 73,030	$ 64,212	$ 63,849	$ 67,371	$ 56,555	$ 45,837	$ 43,853	$ 128,061	$ 201,165	$ 270,883	$ 213,616	$ 208,816
Cost of sales	47,683	58,487	45,830	45,112					90,942	149,642	197,112	162,622	143,851
Gross profit	22,109	14,543	18,382	18,737	18,221	16,310	8,720	7,743	37,119	51,523	73,771	50,994	64,965
Operating expenses:
Selling and commissions		4,064	3,452	3,095					6,547	10,398	14,142	13,117	13,780
Research and development		1,714	1,481	820					2,301	4,015	6,126	4,747	5,578
General and administrative		3,896	3,015	3,730					6,745	10,641	15,289	14,285	13,098
Total selling and commissions, research and development, general and administrative		9,674	7,948	7,645					15,593	25,054	35,557	32,149	32,456
Business development	(132)	463	169	75	746	100		35	244	707	575	881	504
Certain transaction costs (Note 3)		461	416						416	877	1,147
Restructuring costs (Note 4)		631								631	782
Gain on effective settlement of contract (Note 3)		(15,264)								(15,264)	(15,264)
Total operating expenses		(4,035)	8,533	7,720					16,253	12,005	22,797	33,030	32,960
Operating income		18,578	9,849	11,017					20,866	39,518	50,974	17,964	32,005
Other (income)/expense:
Interest expense		7,623	6,069	5,994					12,063	19,686	27,687	24,579	24,010
Debt prepayment expense													295
Other (income)/expense, net		306	(685)	(787)					(1,472)	(1,092)	(1,216)	(1,572)	(459)
Total other expenses, net		7,929	5,384	5,207					10,591	18,594	26,471	23,007	23,846
Income (loss) before provision for income taxes		10,649	4,465	5,810					10,275	20,924	24,503	(5,043)	8,159
Income tax expense		(208)	78	681					759	551	1,636	1,815	3,171
Net income (loss)		10,857	4,387	5,129					9,516	20,373	22,867	(6,858)	4,988
As Previously Reported
Consolidated Statements of Operations
Net sales		73,238	64,235	63,849					128,084	201,396	277,948	213,354	208,816
Cost of sales		58,655	45,765	45,098					90,863	149,731	201,241	162,622	143,851
Gross profit		14,583	18,470	18,751					37,221	51,665	76,707	50,732	64,965
Operating expenses:
Selling and commissions		3,843	3,582	3,174					6,756	10,386	14,143	13,117	13,780
Research and development		1,710	1,480	819					2,299	4,009	6,127	4,747	5,578
General and administrative		3,886	3,237	3,725					6,962	10,848	15,297	14,285	13,098
Total selling and commissions, research and development, general and administrative		9,439	8,299	7,718					16,017	25,243	35,567	32,149	32,456
Certain transaction costs (Note 3)		461	416						416	877	1,147
Restructuring costs (Note 4)		631								631	782
Gain on effective settlement of contract (Note 3)		(15,264)								(15,264)	(15,264)
Total operating expenses		(4,733)	8,715	7,718					16,433	11,487	22,232	32,149	32,456
Operating income		19,316	9,755	11,033					20,788	40,178	54,475	18,583	32,509
Other (income)/expense:
Interest expense		7,623	6,069	5,994					12,063	19,686	27,687	24,579	24,010
Debt prepayment expense													295
Other (income)/expense, net		746	(493)	(712)					(1,205)	(385)	(641)	(691)	45
Total other expenses, net		8,369	5,576	5,282					10,858	19,301	27,046	23,888	24,350
Income (loss) before provision for income taxes		10,947	4,179	5,751					9,930	20,877	27,429	(5,305)	8,159
Income tax expense		(198)	21	681					702	504	1,695	1,750	3,171
Net income (loss)		11,145	4,158	5,070					9,228	20,373	25,734	(7,055)	4,988
Adjustments
Consolidated Statements of Operations
Net sales		(208)	(23)						(23)	(231)	(7,065)	262
Cost of sales		(168)	65	14					79	(89)	(4,129)
Gross profit		(40)	(88)	(14)					(102)	(142)	(2,936)	262
Operating expenses:
Selling and commissions		221	(130)	(79)					(209)	12	(1)
Research and development		4	1	1					2	6	(1)
General and administrative		10	(222)	5					(217)	(207)	(8)
Total selling and commissions, research and development, general and administrative		235	(351)	(73)					(424)	(189)	(10)
Business development		463	169	75					244	707	575	881	504
Total operating expenses		698	(182)	2					(180)	518	565	881	504
Operating income		(738)	94	(16)					78	(660)	(3,501)	(619)	(504)
Other (income)/expense:
Other (income)/expense, net		(440)	(192)	(75)					(267)	(707)	(575)	(881)	(504)
Total other expenses, net		(440)	(192)	(75)					(267)	(707)	(575)	(881)	(504)
Income (loss) before provision for income taxes		(298)	286	59					345	47	(2,926)	262
Income tax expense		(10)	57						57	47	(59)	65
Net income (loss)		$ (288)	$ 229	$ 59					$ 288		$ (2,867)	$ 197