Borrowings - Obligations Under Capital Lease (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Borrowings
Average balance	$ 17,021	$ 13,498	$ 24,830
Weighted average interest rate	4.07%	3.96%	3.07%
Total interest expense	$ 693	$ 536	$ 769
Maximum daily amount outstanding	28,295	20,971	$ 30,044
Unpaid principal balance	$ 20,810	$ 6,605
Weighted average interest rate	3.74%	4.46%
Furniture, fixtures, equipment and building improvements pledged to creditors	$ 20,406	$ 16,281
Capitalized software pledged to creditors	$ 12,192	$ 1,017