Quarterly Financial Information (unaudited) (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
Quarterly Financial Information (unaudited) [Abstract]
Revenues	$ 169,235	[1],[2]	$ 166,615	[2]	$ 162,270	[1]	$ 165,165	[1]	$ 175,180	[3]	$ 166,559		$ 170,214		$ 165,218	[1]	$ 663,285	$ 677,170	$ 688,765
Gross margin	18,326	[1],[2]	26,391	[2]	19,916	[1]	15,083	[1]	28,217	[3]	30,619		32,061		16,300	[1]
Income (loss) before income taxes	(7,591)	[1],[2]	1,108	[2]	(1,650)	[1]	(6,044)	[1]	1,587	[3]	8,542		8,732		(4,116)	[1]	(14,177)	14,746	(142,307)
Net income (loss)	(5,290)	[1],[2]	1,799	[2]	(1,101)	[1]	(3,949)	[1]	604	[3]	5,028		5,057		(2,665)	[1]	(8,541)	8,024	(157,693)
Basic earnings (loss) per share (in dollars per share)	$ (0.15)	[1],[2],[4]	$ 0.05	[2],[4]	$ (0.03)	[1],[4]	$ (0.12)	[1],[4]	$ 0.02	[3],[4]	$ 0.15	[4]	$ 0.15	[4]	$ (0.08)	[1],[4]
Diluted earnings (loss) per share (in dollars per share)	$ (0.15)	[1],[2],[4]	$ 0.05	[2],[4]	$ (0.03)	[1],[4]	$ (0.12)	[1],[4]	$ 0.02	[3],[4]	$ 0.15	[4]	$ 0.15	[4]	$ (0.08)	[1],[4]
Restructuring and related charges																	0	1,773	9,036
Impairment loss																	$ 0	$ 0	$ 183,288

[1] The assumed exercise of stock-based compensation awards for this period was not considered in the calculation of diluted earnings (loss) per share because the impact would have been anti-dilutive.

[2] Includes charges related to non-cash interest associated with amortization of a debt discount of $1.5 million and $1.6 million for the third and fourth quarter, respectively.

[3] Includes charges related to one-time termination benefits associated with capacity realignment of $1.8 million.

[4] We calculated earnings per share for each of the quarters based on the weighted average number of shares and dilutive securities outstanding for each period.  Accordingly, the sum of the quarters may not necessarily be equal to the full year income per share.