Fair Value Disclosures - Level 3 Roll Forward (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Net Asset (Liability) Value [Roll Forward]
Beginning balance	$ 141	$ 27,436
Additions	(6,092)	(1,454)
Payments received	(123)	(1,461)
(Decrease) Increase in value	5,326	2,024
Transfer from Level 3	0	(26,404)
Transfer into Level 3	10,000	0
Ending balance	9,252	141
Derivative Financial Instruments, Liabilities [Member] | Credit Risk Contract [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	(176)	(72)
Additions	(6,092)	(1,454)
Payments received	0	0
(Decrease) Increase in value	5,733	1,350
Transfer from Level 3	0	0
Transfer into Level 3	0	0
Ending balance	(535)	(176)
Corporate Debt Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	0	25,729
Additions	0	0
Payments received	0	0
(Decrease) Increase in value	(400)	675
Transfer from Level 3	0	(26,404)
Transfer into Level 3	10,000	0
Ending balance	9,600	0
Loans [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	317	1,779
Additions	0	0
Payments received	(123)	(1,461)
(Decrease) Increase in value	(7)	(1)
Transfer from Level 3	0	0
Transfer into Level 3	0	0
Ending balance	$ 187	$ 317