Fair Values of Assets and Liabilities Summary of Fair Value Hierarchy for Liabilities (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Nov. 30, 2005	May 31, 2005
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
CAR revolving credit facility	$ 28,500	$ 22,000
ACC amortizing debt facility	125	928
Amortizing debt facilities	42,200	21,411
Revolving credit facility	4,000	4,000
U.K. credit card accounts revolving credit facility	3,924	8,245
Notes Payable, Related Parties	20,000	0
5.875% convertible senior notes	64,302	95,484
Liabilities carried at fair value
Interest rate swap underlying CAR facility	0	97
Economic sharing arrangement liability	119	354
Notes payable associated with structured financings, at fair value	36,511	94,523
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
CAR revolving credit facility	0	0
ACC amortizing debt facility	0	0
Amortizing debt facilities	0	0
Revolving credit facility	0	0
U.K. credit card accounts revolving credit facility	0	0
Notes Payable, Related Parties	0	0
5.875% convertible senior notes	0	0
Liabilities carried at fair value
Interest rate swap underlying CAR facility	0	0
Economic sharing arrangement liability	0	0
Notes payable associated with structured financings, at fair value	0	0
Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
CAR revolving credit facility	0	0
ACC amortizing debt facility	0	0
Amortizing debt facilities	0	0
Revolving credit facility	0	0
U.K. credit card accounts revolving credit facility	0	0
Notes Payable, Related Parties	0	0
5.875% convertible senior notes	37,662	57,007
Liabilities carried at fair value
Interest rate swap underlying CAR facility	0	97
Economic sharing arrangement liability	0	0
Notes payable associated with structured financings, at fair value	0	0
Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
CAR revolving credit facility	28,500	22,000
ACC amortizing debt facility	125	928
Amortizing debt facilities	42,200	21,411
Revolving credit facility	4,000	4,000
U.K. credit card accounts revolving credit facility	3,924	8,245
Notes Payable, Related Parties	20,000	0
5.875% convertible senior notes	0	0
Liabilities carried at fair value
Interest rate swap underlying CAR facility	0	0
Economic sharing arrangement liability	119	354
Notes payable associated with structured financings, at fair value	$ 36,511	$ 94,523
Five Point Eight Seven Five Percent Convertible Senior Notes Due Two Thousand Thirty Five [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Instrument, Interest Rate, Stated Percentage			5.875%	5.875%