Investments - Investment Summary (Details) - Level 2 - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Schedule of Held-to-maturity Securities [Line Items]
Amortized Costs	$ 18,558	$ 10,010
Gross Unrealized Gains	426	154
Gross Unrealized Losses	(5)	0
Fair Value	18,979	10,164
U.S. Treasury bills
Schedule of Held-to-maturity Securities [Line Items]
Amortized Costs	10,784	7,982
Gross Unrealized Gains	270	120
Gross Unrealized Losses	0	0
Fair Value	11,054	8,102
Corporate bonds
Schedule of Held-to-maturity Securities [Line Items]
Amortized Costs	1,705	887
Gross Unrealized Gains	70	17
Gross Unrealized Losses	0	0
Fair Value	1,775	904
Collateralized mortgage obligations
Schedule of Held-to-maturity Securities [Line Items]
Amortized Costs	5,472	545
Gross Unrealized Gains	56	6
Gross Unrealized Losses	(5)	0
Fair Value	5,523	551
Yankees
Schedule of Held-to-maturity Securities [Line Items]
Amortized Costs	597	596
Gross Unrealized Gains	30	11
Gross Unrealized Losses	0	0
Fair Value	$ 627	$ 607