Allowance for Doubtful Accounts (Tables)

12 Months Ended

Dec. 31, 2016

Receivables [Abstract]

Allowance for Doubtful Debts

In order to provide for these collection problems and the general risk associated with the granting of credit terms, we have recorded the following bad debt provisions (in an Allowance for Doubtful Accounts):

	Year Ended December 31,
	2016		2015		2014
	(in thousands)
Bad debt provision	$	4,629	$	4,335	$	4,470

Impaired Notes Receivable

Summary schedules of impaired notes receivable, and the related reserve, for the years ended December 31, 2016, 2015 and 2014 are as follows:

	Impaired Notes Receivable
Year Ended December 31,	Balance Beginning of Year		Additions		Deductions		Balance End of Year		Average Outstanding Balance
	(in thousands)
2016	$	6,471	$	—	$	786	$	5,685	$	6,078
2015	$	10,208	$	395	$	4,132	$	6,471	$	8,340
2014	$	2,892	$	9,124	$	1,808	$	10,208	$	6,550

	Reserve for Impaired Notes Receivable
Year Ended December 31,	Balance Beginning of Year		Additions		Deductions		Balance End of Year
	(in thousands)
2016	$	2,139	$	280	$	—	$	2,419
2015	$	3,031	$	99	$	991	$	2,139
2014	$	2,019	$	2,489	$	1,477	$	3,031