Receivables and Allowance for Doubtful Accounts (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Changes in Allowance for Doubtful Accounts (Table Details) [Abstract]
Beginning balance	$ 2,920,000	$ 3,919,000	$ 5,152,000
Bad debt expense	14,589,000	12,953,000	14,227,000
Accounts written off	(18,348,000)	(17,432,000)	(19,769,000)
Recoveries	4,539,000	3,480,000	4,309,000
Ending balance	3,700,000	2,920,000	3,919,000
Receivables [Line Items]
Receivable, gross	62,386,000	55,739,000
Receivables, net	58,686,000	52,819,000
Installment Sales Receivable [Member]
Receivables [Line Items]
Receivable, gross	51,335,000	46,753,000
Allowance for doubtful accounts	2,900,000	2,320,000
Trade and Notes Receivables [Member]
Receivables [Line Items]
Receivable, gross	11,051,000	8,986,000
Allowance for doubtful accounts	$ 800,000	$ 600,000