Special Charges (Credits) - Narrative (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2022 USD ($)	Mar. 31, 2021 USD ($) employee
Restructuring Cost and Reserve [Line Items]
(Gains) losses on sale of assets and other special charges	$ 8,000	$ (16,000)
Debt extinguishment costs	7,000
Government assistance received		2,600,000
Government assistance received through unsecured loans		753,000
Severance and benefit costs	0	417,000
Nonoperating special termination benefits	0	(46,000)
Nonoperating unrealized gains (losses)	0	(22,000)
Unsecured Debt
Restructuring Cost and Reserve [Line Items]
Long-term debt	$ 400,000
Payroll Support Program 2 & 3 (PSP 2 & 3) Warrants
Restructuring Cost and Reserve [Line Items]
Issuance of warrants		47,000
PSP 2 & 3 Note
Restructuring Cost and Reserve [Line Items]
Grant income		$ 1,800,000
Employee Separation | Voluntary Separation Leave Programs
Restructuring Cost and Reserve [Line Items]
Number of employees electing to voluntarily separate from the company | employee		4,500
Nonoperating special termination benefits		$ 46,000
Employee Separation | Voluntary Separation Leave Programs | Full-Time Employees
Restructuring Cost and Reserve [Line Items]
One-time per employee contribution for special termination benefits related to VSL programs		125
Employee Separation | Voluntary Separation Leave Programs | Part-Time Employees
Restructuring Cost and Reserve [Line Items]
One-time per employee contribution for special termination benefits related to VSL programs		$ 75