Commercial Bank Financing Facility (Details) (USD $)	0 Months Ended			12 Months Ended
	Aug. 05, 2014	May 20, 2014	Apr. 26, 2012	Dec. 31, 2014	May 19, 2014	Dec. 31, 2013
Secured Syndicated Credit Facility | Regions Bank
Line of Credit Facility [Line Items]
Debt instrument, face amount	$ 150,000,000
Deferred Costs, Credit Card Origination Costs, Amount				1,300,000
Secured Syndicated Credit Facility | Citi Bank
Line of Credit Facility [Line Items]
Debt instrument, face amount			100,000,000
Interest Rate at Period End				1.67%
Deferred Costs, Credit Card Origination Costs, Amount			744,000
Secured Syndicated Credit Facility | Revolving Credit Facility | Regions Bank
Line of Credit Facility [Line Items]
Debt Instrument, Term	5 years
Current Borrowing Capacity	150,000,000
Credit agreement, maximum borrowing capacity	200,000,000
Line of Credit Facility, Expansion	50,000,000
Line of credit, interest rate at period end				1.94%
Secured Syndicated Credit Facility | Revolving Credit Facility | Citi Bank
Line of Credit Facility [Line Items]
Revolving credit facility, term			4 years	4 years
Credit agreement, maximum borrowing capacity			45,000,000
Line of Credit Facility, Expansion			10,000,000
Credit agreement, amount outstanding				120,470,000	7,840,000	22,800,000
Repayments of Lines of Credit		15,000,000
Line of credit, interest rate at period end				1.94%
Credit agreement, average amount outstanding during period				40,500,000
Credit agreement, maximum amount outstanding during period				120,470,000
Weighted average interest rate				1.78%		1.67%
Seventh Amendment | BOA
Line of Credit Facility [Line Items]
Debt instrument, face amount			55,000,000
Secured Term Loan | Secured Syndicated Credit Facility | Citi Bank
Line of Credit Facility [Line Items]
Debt instrument, face amount			45,000,000
Credit agreement, amortization period				4 years
Repayments of term loan				7,600,000
Other Long-term Debt				$ 0
Minimum | Secured Syndicated Credit Facility | Regions Bank
Line of Credit Facility [Line Items]
Basis spread on variable interest rate	1.75%
Minimum | Secured Syndicated Credit Facility | Citi Bank
Line of Credit Facility [Line Items]
Basis spread on variable interest rate				1.50%
Maximum | Secured Syndicated Credit Facility | Regions Bank
Line of Credit Facility [Line Items]
Basis spread on variable interest rate	2.25%
Maximum | Secured Syndicated Credit Facility | Citi Bank
Line of Credit Facility [Line Items]
Basis spread on variable interest rate				2.00%