Loans Receivable - Aging of the Loans Receivable Balance (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Financing Receivable, Past Due [Line Items]
Past due loans receivable	15.20%	14.60%
Current loans receivable	84.80%	85.40%
Balance of Credit Card Loans on Nonaccrual Status	$ 2,330	$ 2,110
30-59 days past due
Financing Receivable, Past Due [Line Items]
Past due loans receivable	6.60%	6.90%
60-89 days past due
Financing Receivable, Past Due [Line Items]
Past due loans receivable	3.60%	3.40%
90 or more days past due
Financing Receivable, Past Due [Line Items]
Past due loans receivable	5.00%	4.30%
Balance of Loans Receivable 90 or More Days Past Due and Still Accruing Interest and Fees	$ 0	$ 0