Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Valuation allowance, deferred tax asset, amount increase (decrease)	$ 139,000	$ 28,300
Research Tax Credit Carryforward
Tax credit carryforward	35,100
Domestic
Operating loss carryforwards, subject to expiration	1,300,000
State and Local Jurisdiction
Operating loss carryforwards, subject to expiration	756,000
Foreign
Operating loss carryforwards, subject to expiration	$ 42,700