Student Loans - Credit Quality Indicators (Details) $ in Thousands	Sep. 30, 2020 USD ($) loan	Dec. 31, 2019 USD ($) loan	Sep. 30, 2019 USD ($)
Financing Receivable, Credit Quality Indicator [Line Items]
Loans outstanding	$ 661,482	$ 597,374	$ 570,128
Accrued Interest	$ 10,099	$ 8,208
Student loan
Financing Receivable, Credit Quality Indicator [Line Items]
Number of Loans | loan	1,350	1,505
Loans outstanding	$ 58,677	$ 65,800
Accrued Interest	$ 6,549	$ 5,678
Student loan | School
Financing Receivable, Credit Quality Indicator [Line Items]
Number of Loans | loan	320	601
Loans outstanding	$ 12,758	$ 24,198
Accrued Interest	$ 2,940	$ 4,689
Student loan | Grace
Financing Receivable, Credit Quality Indicator [Line Items]
Number of Loans | loan	212	49
Loans outstanding	$ 9,379	$ 1,598
Accrued Interest	$ 2,434	$ 394
Student loan | Repayment
Financing Receivable, Credit Quality Indicator [Line Items]
Number of Loans | loan	547	507
Loans outstanding	$ 24,322	$ 24,986
Accrued Interest	$ 577	$ 203
Student loan | Deferment
Financing Receivable, Credit Quality Indicator [Line Items]
Number of Loans | loan	162	124
Loans outstanding	$ 7,044	$ 4,392
Accrued Interest	$ 445	$ 204
Student loan | Forbearance
Financing Receivable, Credit Quality Indicator [Line Items]
Number of Loans | loan	109	224
Loans outstanding	$ 5,174	$ 10,626
Accrued Interest	$ 153	$ 188