Receivables (Narrative) (Details) (USD $)	3 Months Ended
	Mar. 31, 2015 payment	Dec. 31, 2014
Receivables [Abstract]
Allowance for doubtful accounts receivable	$ 12,301,000	$ 12,988,000
Number of missed payments before delinquent	3
Typical financing period	12 months
Credit amount requiring additional analysis	250,000
Average period of adjudication	18 months
Installment receivable purchased from DLL	$ 647,000