Short-Term Borrowings (Details) (USD $)			0 Months Ended	9 Months Ended			0 Months Ended		9 Months Ended
	Sep. 30, 2014	Dec. 31, 2013	Mar. 14, 2014 Line of Credit [Member] 2014 Debt Agreement [Member]	Sep. 30, 2014 Convertible Senior Notes [Member] 2015 Convertible Senior Notes [Member]	Dec. 31, 2013 United States Accounts Receivable Balance [Member] Line of Credit [Member] 2014 Debt Agreement [Member]	Dec. 31, 2013 Foreign Accounts Receivable Balance [Member] Line of Credit [Member] 2014 Debt Agreement [Member]	Mar. 14, 2014 Maximum [Member] Line of Credit [Member] 2014 Debt Agreement [Member] Prime Rate [Member]	Mar. 14, 2014 Minimum [Member] Line of Credit [Member] 2014 Debt Agreement [Member] Prime Rate [Member]	Sep. 30, 2014 Letter of Credit [Member] Line of Credit [Member] 2014 Debt Agreement [Member]	Mar. 14, 2014 Letter of Credit [Member] Line of Credit [Member] 2014 Debt Agreement [Member]	Mar. 11, 2014 Letter of Credit [Member] Line of Credit [Member] 2014 Debt Agreement [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 35,000,000
Line of Credit Facility, Current Borrowing Capacity			25,000,000.0							2,000,000	1,000,000
Line of Credit Facility, Borrowing Formula, Eligible Accounts Receivable					80.00%	65.00%
Line of Credit Facility, Borrowing Formula, Eligible Accounts Receivable, Days from Invoice Date									60 days
Line of Credit Facility, Remaining Borrowing Capacity	14,000,000
Line of Credit, Liquidity Threshold			15,000,000
Line of Credit, Liquidity Threshold, Last Month of Quarter			20,000,000
Debt instrument, interest rate, stated percentage				4.50%
Debt Instrument, Liquidity Threshold, Period Prior to Maturity Date				120 days
Line of Credit, Modification Fee			35,000
Line of Credit Facility, Commitment Fee Amount			35,000
Debt Instrument, Average Monthly Interest Expense			10,000,000
Debt Instrument, Basis Spread on Variable Rate							2.25%	0.75%
Line of Credit Facility, Cancellation Fee Percentage			1.50%
Line of Credit Facility, Debt Covenant, Liquidity			10,000,000
Line of Credit Facility, Amount Outstanding	$ 10,000,000	$ 15,000,000