Commercial Bank Financing Facility (Details) (USD $)	12 Months Ended					12 Months Ended		0 Months Ended		12 Months Ended		12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 Secured Syndicated Credit Facility [Member] Citi Bank [Member]	Apr. 26, 2012 Secured Syndicated Credit Facility [Member] Citi Bank [Member]	Dec. 31, 2012 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]	Apr. 26, 2012 Credit Agreement, Seventh Amendment [Member] BOA [Member]	Dec. 31, 2012 Credit Agreement, Seventh Amendment [Member] Revolving Credit Facility [Member] BOA [Member]	Dec. 31, 2012 Secured Term Loan [Member] Secured Syndicated Credit Facility [Member] Citi Bank [Member]	Apr. 26, 2012 Secured Term Loan [Member] Secured Syndicated Credit Facility [Member] Citi Bank [Member]	Dec. 31, 2012 Secured Term Loan [Member] Credit Agreement, Seventh Amendment [Member] BOA [Member]	Dec. 31, 2011 Secured Term Loan [Member] Credit Agreement, Seventh Amendment [Member] BOA [Member]	Dec. 31, 2012 Minimum [Member] Secured Syndicated Credit Facility [Member] Citi Bank [Member]	Dec. 31, 2012 Mid-range [Member] Secured Syndicated Credit Facility [Member] Citi Bank [Member]	Dec. 31, 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
Revolving 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
Basis spread on variable interest rate														1.50%	1.71%	2.00%
Deferred Costs, Credit Card Origination Costs, Amount				620,000	744,000
Repayments of term loan	600,000	0	0					45,140,000		4,100,000		1,700,000
Credit agreement, amount outstanding						37,800,000			31,800,000
Line of credit, interest rate at period end						1.71%			1.75%
Credit agreement, average amount outstanding during period						32,400,000
Credit agreement, maximum amount outstanding during period						37,800,000
Debt, Weighted Average Interest Rate						1.74%
Long-term Debt	81,273,000									40,900,000			15,000,000
Credit agreement, current amount outstanding										$ 11,300,000
Current maturities, period										12 months
Effective interest rate										1.71%