Borrowings Revolving line of credit (Details) (USD $) In Millions, unless otherwise specified	0 Months Ended			9 Months Ended
	Apr. 04, 2012	Mar. 23, 2012	Feb. 13, 2012	Sep. 30, 2012	Dec. 31, 2011
Debt Instrument [Line Items]
Number of debt instruments				2
Revolving Credit Facility
Debt Instrument [Line Items]
Revolving line of credit, maximum borrowing capacity				$ 5.0
Borrowing base, percent of eligible accounts receivable				80.00%
Variable rate basis				bank’s prime rate
Basis spread on variable rate				1.00%
Revolving line of credit outstanding	4.5				4.5
Repayments	4.5		4.5
Additional borrowings		$ 4.5
Revolving Credit Facility | Minimum
Debt Instrument [Line Items]
Variable rate basis				30-Day LIBOR rate
Basis spread on variable rate				2.50%