Loans and Finance Receivables and Allowance for Credit Losses (Aging Analysis of Term Loans) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Financing Receivable, Past Due [Line Items]
Current loans and finance receivables	$ 1,098,064	$ 1,031,449
Total unpaid principal balance	1,238,409	1,144,954
1-14 calendar days past due
Financing Receivable, Past Due [Line Items]
Past due loans	28,375	27,655
15-29 calendar days past due
Financing Receivable, Past Due [Line Items]
Past due loans	17,383	14,665
30-59 calendar days past due
Financing Receivable, Past Due [Line Items]
Past due loans	25,067	21,470
60-89 calendar days past due
Financing Receivable, Past Due [Line Items]
Past due loans	22,004	19,031
90 calendar days past due
Financing Receivable, Past Due [Line Items]
Past due loans	$ 47,516	$ 30,684