Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets:
Loan reserves	$ 109,369	$ 85,100
Stock-based compensation plans	10,022	9,312
Deferred revenue	1,017	1,081
Operating loss carryovers	0	0
Accrued expenses not currently deductible	12,599	12,896
Net unrealized losses	2,124	0
Unrecorded tax benefits	6,049	5,106
Market value adjustments on student loans, investments and derivatives	0	1,460
Other	874	953
Total deferred tax assets	142,054	115,908
Deferred tax liabilities:
Fixed assets	10,475	7,150
Acquired intangible assets	5,453	5,179
Market value adjustments on student loans, investments and derivatives	3,175	0
Net unrealized gains	0	3,436
Federal deferred for state receivable	5,368	2,083
Student loan premiums and discounts, net	3,398	1,971
Other	285	285
Total deferred tax liabilities	28,154	20,104
Net deferred tax assets	$ 113,900	$ 95,804