Borrowings - Obligations Under Capital Lease (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Leases
Average balance	$ 25,812	$ 11,615	$ 13,380	$ 15,187
Weighted average interest rate	4.47%	4.09%	4.48%	3.87%
Total interest expense	$ 274	$ 122	$ 476	$ 444
Unpaid principal balance	$ 23,881		$ 23,881		$ 6,605
Weighted average interest rate	4.45%		4.45%		4.46%
Furniture, fixtures, equipment and building improvements pledged to creditors	$ 22,172		$ 22,172		$ 16,281
Capitalized software pledged to creditors	14,090		14,090		$ 1,017
Maximum
Leases
Maximum daily amount outstanding	$ 28,295	$ 13,032	$ 28,295	$ 20,971