Purchased Receivables - Summary Of Components Of Net Purchased Receivables (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Purchased Receivables [Abstract]
Purchased receivables	$ 14,596	$ 22,431
Reserve for purchased receivable losses	(190)	(200)	$ (171)	$ (181)
Total	$ 14,406	$ 22,231