Receivables and Allowance for Doubtful Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Receivables [Line Items]
Receivable, gross	$ 73,378	$ 72,934
Receivables, net	69,785	69,320
Changes in Allowance for Doubtful Accounts [Roll Forward]
Beginning balance	(3,614)	(4,023)	$ (3,700)
Bad debt expense	(15,449)	(15,260)	(15,509)
Accounts written off	16,095	16,317	15,718
Recoveries	625	648	532
Ending balance	(3,593)	(3,614)	$ (4,023)
Installment Sales Receivable [Member]
Receivables [Line Items]
Receivable, gross	55,834	57,010
Changes in Allowance for Doubtful Accounts [Roll Forward]
Beginning balance	(3,400)
Ending balance	(3,300)	(3,400)
Trade and Notes Receivables [Member]
Receivables [Line Items]
Receivable, gross	14,067	15,924
Changes in Allowance for Doubtful Accounts [Roll Forward]
Beginning balance	(200)
Ending balance	(300)	(200)
Other receivables [Member]
Receivables [Line Items]
Receivable, gross	$ 3,477	$ 0