Receivables Narrative (Details) (USD $)	6 Months Ended
	Jun. 30, 2012	Dec. 31, 2011
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for Doubtful Accounts Receivable	$ 25,402,000	$ 27,947,000
Credit amount requiring additional analysis	250,000
Average Period of Adjudication	18 months
Installment receivable purchased from DLL	$ 1,661,000
U.S.
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Missed Payments before Delinquent	3
CANADA
Accounts, Notes, Loans and Financing Receivable [Line Items]
Typical Financing Period	12 months