Current Liabilities and Debt Obligations (Details) (USD $)	3 Months Ended		9 Months Ended		12 Months Ended				9 Months Ended					3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2010	Dec. 31, 2012	May 11, 2012 Senior Redeemable Preferred Stock [Member]	Sep. 30, 2013 LIBOR Rate [Member]	Sep. 30, 2013 Term Loan [Member]	Jul. 31, 2013 Term Loan [Member]	Dec. 31, 2012 Term Loan [Member]	Sep. 30, 2013 Term Loan [Member] Federal Funds Rate [Member]	Sep. 30, 2013 Term Loan [Member] LIBOR Rate [Member]	Sep. 30, 2013 Revolving credit [Member]	Sep. 30, 2012 Revolving credit [Member]	Sep. 30, 2013 Revolving credit [Member]	Sep. 30, 2012 Revolving credit [Member]	Sep. 30, 2013 Short-term [Member] Term Loan [Member]		Sep. 30, 2013 Long-term [Member]	Sep. 30, 2013 Long-term [Member] Term Loan [Member]		Sep. 30, 2013 Long-term [Member] Revolving credit [Member]
Accounts Payable and Other Accrued Payables [Abstract]
Trade account payables	$ 22,100,000		$ 22,100,000			$ 16,400,000
Accrued trade payables	13,100,000		13,100,000			6,700,000
Senior Revolving Credit Facility [Abstract]
Maximum revolving credit facility														30,000,000		30,000,000
Term loan component of Facility						6,100,000				6,300,000
Principal amount of term loan repaid in quarterly installments					93,750
Percentage added to reference rate to compute the variable rate (in hundredths)	2.00%		2.00%					3.75%				1.00%	1.50%
Interest rate on credit facility (in hundredths)	4.25%		4.25%
Interest expense	1,381,000	1,603,000	4,154,000	5,083,000										200,000	200,000	600,000	600,000
Discount rate on senior redeemable preferred stock redemption (in hundredths)	10.00%		10.00%				10.00%
Maximum redemption of redeemable preferred stock	2,000,000		2,000,000				4,000,000
Percentage of term loan amortized per year (in hundredths)									5.00%
Amortization of term loan per year			54,000	54,000					400,000
Outstanding borrowing of credit facility	19,300,000		19,300,000			18,900,000			6,300,000		6,600,000							400,000			6,000,000
Remaining borrowing capacity	10,200,000		10,200,000			2,200,000
Weighted average interest rates on outstanding borrowings (in hundredths)	5.30%	5.40%	5.30%	5.40%
Maturities of facility presented by year [Abstract]
2013	375,000		375,000															375,000	[1]	0	0	[1]	0	[2]
2014	18,953,000		18,953,000															0	[1]	18,953,000	5,906,000	[1]	13,047,000	[2]
Total	19,328,000		19,328,000															375,000	[1]	18,953,000	5,906,000	[1]	13,047,000	[2]
Warranty Liability [Abstract]
Accrued warranty liability	$ 100,000		$ 100,000			$ 200,000

[1] The principal will be repaid in quarterly installments of $93,750, with a final installment of the unpaid principal amount payable on May 17, 2014.

[2] Balance due represents balance as of June 30, 2013, with fluctuating balances based on working capital requirements of the Company.