v2.4.0.6
Fair Value Measurements (Fair Value, by Balance Sheet Grouping) (Details) (Parent [Member], Level 3, Fair Value, Measurements, Nonrecurring [Member], USD $)
In Thousands, unless otherwise specified
Mar. 31, 2013
Dec. 31, 2012
Outstanding Face Amount
   
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Notes Receivable $ 2,488 $ 2,470
Obligation Under Assessment Arrangements 38,345 38,787
Other Financial Instruments 500 500
Carrying Value
   
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Notes Receivable 2,488 2,470
Obligation Under Assessment Arrangements 29,049 29,335
Other Financial Instruments 421 413
Estimate Fair Value
   
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Notes Receivable 2,488 2,470
Obligation Under Assessment Arrangements 28,795 29,113
Other Financial Instruments $ 421 $ 413