Income Taxes - Deferred Tax Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Deferred Tax Assets:
Investment in Spark HoldCo	$ 25,751	$ 28,671
State net operating loss carryforward	0	140
Derivative Liabilities	416	1,669
Intangibles	1,393	0
Other	531	220
Total deferred tax assets	28,091	30,700
Deferred Tax Liabilities:
Intangibles	0	(808)
Property and equipment	0	(27)
Other	(131)	0
Total deferred tax liabilities	(131)	(835)
Total deferred tax assets/liabilities	$ 27,960	$ 29,865