Cash, Cash Equivalents and Available for Sale Securities (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period	$ 238,041	$ 101,733	$ 117,203	$ 123,959
Balance at end of period	214,586	89,462	214,586	89,462
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period	0	0	0	0
Current period changes in fair value before reclassifications, net of tax	1	0	1	0
Amounts reclassified from accumulated other comprehensive income, net of tax	0	0	0	0
Total other comprehensive income	1	0	1	0
Balance at end of period	$ 1	$ 0	$ 1	$ 0