Debt with Commercial Bank (Narrative) (Details) (USD $)	3 Months Ended		0 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Aug. 05, 2014	Apr. 26, 2012	May 19, 2014	Feb. 03, 2015
Line of Credit Facility [Line Items]
Document Period End Date	Mar. 31, 2015
Principal payments of debt obligations	$ (12,000)	$ (9,000)
Secured Syndicated Credit Facility [Member] | Regions Bank [Member]
Line of Credit Facility [Line Items]
Debt instrument, face amount			150,000,000
Deferred Costs, Credit Card Origination Costs, Amount	1,500,000
Secured Syndicated Credit Facility [Member] | Citi Bank [Member]
Line of Credit Facility [Line Items]
Debt instrument, face amount				100,000,000
Secured Syndicated Credit Facility [Member] | Revolving Credit Facility [Member] | Regions Bank [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Term			5 years
Credit agreement, maximum borrowing capacity			200,000,000
Line of Credit Facility, Expansion			50,000,000
Credit agreement, amount outstanding	135,465,000
Principal payments of debt obligations	0
Secured Syndicated Credit Facility [Member] | Revolving Credit Facility [Member] | Citi Bank [Member]
Line of Credit Facility [Line Items]
Credit agreement, amount outstanding					7,840,000
Line of credit, interest rate at period end	1.69%
Principal payments of debt obligations	(15,000,000)
Credit agreement, average amount outstanding during period	127,400,000
Credit agreement, maximum amount outstanding during period	135,500,000
Secured Syndicated Credit Facility, First Amendment [Member] | Regions Bank [Member]
Line of Credit Facility [Line Items]
Debt instrument, face amount			150,000,000			190,000,000
Line of Credit, Accordion						50,000,000
Line of Credit Facility, Expansion						90,000,000
Secured Syndicated Credit Facility, First Amendment [Member] | Revolving Credit Facility [Member] | Regions Bank [Member]
Line of Credit Facility [Line Items]
Credit agreement, maximum borrowing capacity			$ 200,000,000			$ 240,000,000
Minimum [Member] | Secured Syndicated Credit Facility [Member] | Regions Bank [Member]
Line of Credit Facility [Line Items]
Basis spread on variable interest rate			1.50%
Mid-range [Member] | Secured Syndicated Credit Facility [Member] | Regions Bank [Member]
Line of Credit Facility [Line Items]
Basis spread on variable interest rate			1.6875%
Maximum [Member] | Secured Syndicated Credit Facility [Member] | Regions Bank [Member]
Line of Credit Facility [Line Items]
Basis spread on variable interest rate			2.25%