Income Taxes - Carryforwards and Limitations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Income taxes
Tax credit carryforwards subject to expiration and IRC Section 382 limitation		$ 3,500
Other future tax deductible amounts subject to IRC Section 382 limitation		40,800
Reduction in deferred tax assets for tax effect of lost benefits under IRC Section 382		67,200
Reduction in deferred tax valuation allowance for tax effect of lost benefits under IRC Section 382		67,200
Minimum
Income taxes
Percentage of change in ownership	50.00%
State
Income taxes
Net operating loss carryforwards amount		200
Foreign
Income taxes
Net operating loss carryforwards amount	$ 220,900	198,300
U.S. federal
Income taxes
Net operating loss carryforwards amount	68,000	47,500
Net operating loss carryforwards subject to expiration and IRC Section 382 limitation	$ 1,200	$ 300