Receivables (Installment Recevables) (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015	Dec. 31, 2014
Receivables [Abstract]
Non-Impaired Financing Receivable, Related Allowance	$ 0	$ 0
Installment Receivables, Current	2,134	2,309
Installment Receivables, Long-Term	3,166	2,318
Total Installment Receivables	5,300	4,627
Unearned Interest	49	42
Unearned Interest, Noncurrent	0	0
Total Unearned Interest	(49)	(42)
Installment Receivables Net of Unearned Interest Current	2,085	2,267
Installment Receivables Net of Unearned Interest Noncurrent	3,166	2,318
Installment Receivables, Net of Unearned Interest	5,251	4,585
Allowance for doubtful accounts, current	(629)	(1,122)
Allowance for doubtful accounts, long-term	(2,812)	(1,670)
Allowance for doubtful accounts	(3,441)	(2,792)	$ (5,852)
Installment receivables, net	1,456	1,145
Installment receivables, net, long-term	354	648
Installment receivables, net	$ 1,810	$ 1,793