Receivables and Allowance for Doubtful Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Receivables [Line Items]
Receivable, gross	$ 72,934	$ 69,515
Receivables, net	69,320	65,492
Changes in Allowance for Doubtful Accounts [Roll Forward]
Beginning balance	(4,023)	(3,700)	$ (2,920)
Bad debt expense	15,260	15,509	14,589
Allowance for Doubtful Accounts Receivable, Write-offs	16,317	15,718	14,271
Allowance for Doubtful Accounts Receivable, Recoveries	648	532	462
Ending balance	(3,614)	(4,023)	$ (3,700)
Installment Sales Receivable [Member]
Receivables [Line Items]
Receivable, gross	57,010	56,516
Changes in Allowance for Doubtful Accounts [Roll Forward]
Beginning balance	(3,509)
Ending balance	(3,364)	(3,509)
Trade and Notes Receivables [Member]
Receivables [Line Items]
Receivable, gross	15,924	12,999
Changes in Allowance for Doubtful Accounts [Roll Forward]
Beginning balance	(514)
Ending balance	$ (249)	$ (514)