Special Credits - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Unusual or Infrequent Item, or Both [Line Items]
Special credits	$ (115,002)	$ (151,911)	$ (291,940)	$ (151,911)
Payroll Support Program 2 and 3, Grant, CARES Act
Unusual or Infrequent Item, or Both [Line Items]
Special credits	99,300		255,800
CARES Act Employee Retention Credit
Unusual or Infrequent Item, or Both [Line Items]
Special credits	16,300	28,000	37,500	28,000
Payroll Support Program 2
Unusual or Infrequent Item, or Both [Line Items]
Severance costs and costs for voluntary separations	$ 600		$ 1,400
Payroll Support Program, CARES Act
Unusual or Infrequent Item, or Both [Line Items]
Special credits		$ 123,900		$ 123,900