Purchased Receivables - Narrative (Details)	12 Months Ended
	Dec. 31, 2018 USD ($) segment purchased_receivable	Dec. 31, 2017 USD ($) purchased_receivable	Dec. 31, 2016 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Maturity of purchased receivables (less than)	1 year
Number of segments and classes of purchased receivables | segment	1
Restructured purchased receivables	$ 14,831,000	$ 23,800,000
Charge-offs	$ 1,926,000	$ 1,744,000	$ 1,482,000
Purchased Receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Purchased receivables past due | purchased_receivable	0	0
Restructured purchased receivables	$ 0	$ 0	0
Charge-offs	$ 0	$ 0	$ 0