Debt with Commercial Bank (Narrative) (Details) (USD $)	6 Months Ended				0 Months Ended		6 Months Ended			0 Months Ended	6 Months Ended	0 Months Ended	6 Months Ended	0 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013 Secured Syndicated Credit Facility [Member] Citi Bank [Member]	Apr. 26, 2012 Secured Syndicated Credit Facility [Member] Citi Bank [Member]	Jul. 30, 2013 Secured Syndicated Credit Facility [Member] Revolving Credit Facility [Member] Citi Bank [Member]	Apr. 26, 2012 Secured Syndicated Credit Facility [Member] Revolving Credit Facility [Member] Citi Bank [Member]	Jun. 30, 2013 Secured Syndicated Credit Facility [Member] Revolving Credit Facility [Member] Citi Bank [Member]	Aug. 07, 2013 Secured Syndicated Credit Facility [Member] Revolving Credit Facility [Member] Citi Bank [Member]	Apr. 26, 2012 Credit Agreement, Seventh Amendment [Member] BOA [Member]	Apr. 26, 2012 Secured Term Loan [Member] Secured Syndicated Credit Facility [Member] Citi Bank [Member]	Jun. 30, 2013 Secured Term Loan [Member] Secured Syndicated Credit Facility [Member] Citi Bank [Member]	Apr. 26, 2012 Minimum [Member] Secured Syndicated Credit Facility [Member] Citi Bank [Member]	Jun. 30, 2013 Mid-range [Member] Secured Syndicated Credit Facility [Member] Citi Bank [Member]	Apr. 26, 2012 Maximum [Member] Secured Syndicated Credit Facility [Member] Citi Bank [Member]
Line of Credit Facility [Line Items]
Debt instrument, face amount				$ 100,000,000					$ 55,000,000	$ 45,000,000
Line of credit facility, term						4 years
Credit agreement, maximum borrowing capacity						45,000,000
Credit agreement, amortization period										4 years
Line of Credit Facility, Expansion						10,000,000
Description of variable interest rate basis			LIBOR
Basis spread on variable interest rate												1.50%	1.70%	2.00%
Deferred Costs, Credit Card Origination Costs, Amount			527,000	744,000
Credit agreement, amount outstanding							32,800,000	27,800,000
Line of credit, interest rate at period end							1.70%
Principal payments of debt obligations	(624,000)	(600,000)			(5,000,000)		(5,000,000)				(4,100,000)
Credit agreement, average amount outstanding during period							36,400,000
Credit agreement, maximum amount outstanding during period							37,800,000
Long-term Debt											36,800,000
Credit agreement, current amount outstanding											12,400,000
Current maturities, period											12 months
Effective interest rate											1.70%
Long-term Debt, Excluding Current Maturities											$ 24,800,000