Accumulated Other Comprehensive Income - Reclassification out of Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Loss on investments, net	$ (4,400)	$ (20,991)	$ (4,211)	$ (73)
Income tax expense		68,393	(19,376)	44,760
Net Income		698	0	0
Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Loss on investments, net		698	0	0
Income before income taxes		698	0	0
Income tax expense		$ 0	$ 0	$ 0