Basis of Presentation and Significant Accounting Policies - Calculation for Basic and Diluted Earnings Per Share (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended														12 Months Ended
	Dec. 31, 2013		Sep. 30, 2013		Jun. 30, 2013		Mar. 31, 2013		Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012		Mar. 31, 2012		Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Numerator:
Net (loss) income	$ (12,630)	[1]	$ (6,911)	[1]	$ (3,799)	[1]	$ (10,622)	[1]	$ (5,643)	$ 3,173	$ (2,978)	[2]	$ (4,300)	[2]	$ (33,962)	$ (9,748)	$ (1,760)
Denominator:
Weighted average common shares outstanding															23,214	22,993	22,983
Effect of dilutive securities:
Outstanding common stock equivalents															0	0	0
Weighted Average Number of Shares Outstanding, Diluted															23,214	22,993	22,983
Basic (loss) earnings per share	$ (0.54)		$ (0.30)		$ (0.16)		$ (0.46)		$ (0.24)	$ 0.14	$ (0.13)		$ (0.19)		$ (1.46)	$ (0.42)	$ (0.08)
Diluted (loss) earnings per share	$ (0.54)		$ (0.30)		$ (0.16)		$ (0.46)		$ (0.24)	$ 0.13	$ (0.13)		$ (0.19)		$ (1.46)	$ (0.42)	$ (0.08)
Excluded outstanding share-based awards having an anti-dilutive effect															717	994	757
Convertible Debt Securities
Effect of dilutive securities:
Excluded outstanding share-based awards having an anti-dilutive effect															2,032	1,416	1,734

[1] First, second, third and fourth quarter results include restructuring charges of $2,982, $6,072, $885 and $300, respectively. Amounts were included in restructuring charges and cost of materials during the respective quarters.

[2] First and second quarter results include a mark-to-market adjustment related to the conversion option associated with the convertible debt in the amount of $11,340 and $4,257, respectively. Amounts were included in interest expense during the respective quarters.