Income Taxes - Carryforwards (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2020	Dec. 31, 2019
Operating Loss Carryforwards [Line Items]
Discrete income tax expense (benefit), CARES Act, percent		14.00%
Discrete income tax expense (benefit), CARES Act, amount		$ 3,900
Capital losses	$ 26,126	26,126	$ 0
Equity securities impairment loss	2,500	2,500
Valuation allowance	26,985	26,985	$ 2,743
Sale Of Stock By Wholly Owned Subsidiary
Operating Loss Carryforwards [Line Items]
Capital losses	600	600
Equity securities impairment loss	2,500
OF Holdings, Inc.
Operating Loss Carryforwards [Line Items]
Capital losses	25,500	25,500
U.S. federal
Operating Loss Carryforwards [Line Items]
Capital loss carryforwards	103,900	103,900
U.S. state
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	19,000	19,000
Income tax credit carryforwards	400	400
U.S. state | Capital Loss Carryforward
Operating Loss Carryforwards [Line Items]
Valuation allowance	700	700
Domestic Tax Authority
Operating Loss Carryforwards [Line Items]
Valuation allowance released	1,300	1,300
Domestic Tax Authority | Capital Loss Carryforward
Operating Loss Carryforwards [Line Items]
Valuation allowance	26,100	26,100
Foreign Tax Authority | Loss and Other Credit Carryforward
Operating Loss Carryforwards [Line Items]
Valuation allowance	$ 200	$ 200