Convertible Notes, Long-Term Debt and Credit Facility Convertible Notes, Long-Term Debt and Credit Facility (Credit Facility) (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2013 Line of Credit [Member]	Dec. 31, 2013 Term loan [Member]	Dec. 31, 2013 Revolving Credit Facility [Member]	Dec. 31, 2012 Revolving Credit Facility [Member]	Dec. 31, 2013 Revolving Credit Facility [Member] Line of Credit [Member]	Dec. 31, 2013 Term loan [Member] Line of Credit [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity						$ 75,000,000.0
Maturity date			May 10, 2018
Amount borrowed				16,272,000	0	16,300,000	50,000,000
Credit facility, financial covenant debt ratio upper range	110.00%
Credit facility, financial covenant debt ratio lower range	100.00%
Covenant, Maximum Funded Debt to Adjusted EBITDA	4.0
Annual limit on capital expenditures		36,000,000
Covenant, Percent of Adjusted EBITDA Which Must Be Prepaid	25.00%
Credit Facility Ceiling Value, Applicable to 25% Of Adjusted EBITDA Which Must Be Paid	3,000,000
Covenant, Maximum Number of Days From Year End By Which Prepayment of 25% of Adjusted EBTDA is Due	60 days
Excess Cash Flow Minimum Achieved Under Loan Covenant	3,000,000
Amount Company Will Prepay on Term Loan Due To Covenant Requirement	$ 3,000,000