Convertible Notes, Long-Term Debt and Credit Facility (Term Loan) (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Debt Instrument [Line Items]
Debt outstanding	$ 62,105,000
Term loan [Member]
Debt Instrument [Line Items]
Face amount	50,000,000
Monthly principal payments	600,000
Maturity date	May 10, 2018
Percentage of Value of Equipment Held by Lender as Security	85.00%
Eighty-Five Percent of Value of Pledged Equipment Collateral	18,300,000
Percent of FMV of Domestic Lands and Buildings Which Will Support Outstanding Loan Balance as Collateral When Lender Has Secured Related Lien	75.00%
Debt outstanding	45,833,000	25,000,000
PNC Bank base lending rate [Member] | Term loan [Member]
Debt Instrument [Line Items]
Debt outstanding	800,000
Interest rate at period end	4.50%
LIBOR [Member] | Term loan [Member]
Debt Instrument [Line Items]
Debt outstanding	$ 45,000,000
Interest rate at period end	2.42%
Minimum [Member] | PNC Bank base lending rate [Member] | Term loan [Member]
Debt Instrument [Line Items]
Basis spread on variable rate	1.25%
Maximum [Member] | PNC Bank base lending rate [Member] | Term loan [Member]
Debt Instrument [Line Items]
Basis spread on variable rate	1.75%
Term loan [Member] | Minimum [Member] | LIBOR [Member] | Line of Credit [Member]
Debt Instrument [Line Items]
Basis spread on variable rate	2.25%
Term loan [Member] | Maximum [Member] | LIBOR [Member] | Line of Credit [Member]
Debt Instrument [Line Items]
Basis spread on variable rate	2.75%