Income Taxes - Income Tax Expense (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Current tax expense:
Federal		$ 0	$ 0	$ 0
State		194	0	0
Current income tax expense		194	0	0
Deferred
Federal		0	0	0
State		0	0	0
Deferred income tax expense		0	0	0
Total income tax expense	$ 194	$ 194	$ 0	$ 0