Schedule II Valuation and Qualifying Accounts (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011
Allowance for Notes Receivable [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Valuation Allowances and Reserves, Balance at Beginning of Period	$ 778		$ 747
Additions Charged to Operations	262		31
Valuation Allowances and Reserves, Balance at end of Period	1,040		778
Valuation Allowance, Other Tax Carryforward [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Valuation Allowances and Reserves, Balance at Beginning of Period	42,786		35,617
Deductions, Other	8,766	[1]	7,169	[1]
Valuation Allowances and Reserves, Balance at end of Period	$ 51,552		$ 42,786

[1] Includes payments and actual write offs, as well as changes in estimates in the reserves.