Convertible Notes, Long-Term Debt and Credit Facility Convertible Notes, Long-Term Debt and Credit Facility (Credit Facility) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 28, 2012
Debt Instrument [Line Items]
Credit facility, financial covenant debt ratio upper range	110.00%
Credit facility, financial covenant debt ratio lower range	100.00%
Credit facility, covenant terms	The Credit Facility is secured by substantially all of the Company’s domestic personal property, including accounts receivable, inventory, equipment and other intangible assets. The Credit Facility contains customary representations, warranties, and both affirmative and negative covenants, including a financial covenant to maintain consolidated earnings before interest, taxes, depreciation and amortization (“EBITDA”) to debt ratio of 1.10 to 1.00 and an annual limit on capital expenditures of $20 million. The Credit Facility restricts the payment of cash dividends on common stock. In the event of default, PNC Bank may accelerate the maturity date of any outstanding amounts borrowed under the Credit Facility.
Line of Credit [Member]
Debt Instrument [Line Items]
Annual limit on capital expenditures	$ 24
Revolving Credit Facility [Member] | Line of Credit [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity	50
Monthly facility fee	0.25%
Secured amount of credit facility	47.2
Credit facility, interest rate description	The interest rate on advances varies based on the level of borrowings. Rates range (a) between PNC Bank's base lending rate plus 0.5% to 1.0% or (b) between the London Interbank Lending Rate (LIBOR) plus 1.5% to 2.0%. PNC Bank's base lending rate was 3.25% at December 31, 2012 and would have permitted borrowing at rates ranging between 3.75% and 4.25%.
Revolving Credit Facility [Member] | Line of Credit [Member] | PNC Bank base lending rate [Member]
Debt Instrument [Line Items]
Base lending rate	3.25%
Permitted borrowing rate, minimum	4.25%
Permitted borrowing rate, maximum	4.75%
Revolving Credit Facility [Member] | Letter of Credit [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity	10
Term loan [Member] | Line of Credit [Member]
Debt Instrument [Line Items]
Amount borrowed		25
Periodic prinicpal payments	$ 0.3
Credit facility, interest rate at period end	4.75%
Credit facility, interest rate description	The interest rate varies based on the level of borrowings under the revolving credit facility. Rates range (a) between PNC Bank's base lending rate plus 1.0% to 1.5% or (b) between the London Interbank Lending Rate (LIBOR) plus 2.0% to 2.5%. At December 31, 2012, the interest rate on the term loan was 4.25%.
Minimum [Member] | Revolving Credit Facility [Member] | Line of Credit [Member] | PNC Bank base lending rate [Member]
Debt Instrument [Line Items]
Credit facility, variable percentage rate spread	1.00%
Minimum [Member] | Revolving Credit Facility [Member] | Line of Credit [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Credit facility, variable percentage rate spread	2.00%
Minimum [Member] | Term loan [Member] | Line of Credit [Member] | PNC Bank base lending rate [Member]
Debt Instrument [Line Items]
Credit facility, variable percentage rate spread	1.50%
Minimum [Member] | Term loan [Member] | Line of Credit [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Credit facility, variable percentage rate spread	2.50%
Maximum [Member] | Revolving Credit Facility [Member] | Line of Credit [Member] | PNC Bank base lending rate [Member]
Debt Instrument [Line Items]
Credit facility, variable percentage rate spread	1.50%
Maximum [Member] | Revolving Credit Facility [Member] | Line of Credit [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Credit facility, variable percentage rate spread	2.50%
Maximum [Member] | Term loan [Member] | Line of Credit [Member] | PNC Bank base lending rate [Member]
Debt Instrument [Line Items]
Credit facility, variable percentage rate spread	2.00%
Maximum [Member] | Term loan [Member] | Line of Credit [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Credit facility, variable percentage rate spread	3.00%