Special Credits - Narrative (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Unusual or Infrequent Item, or Both [Line Items]
Special credits	$ (148,308,000)	$ 0	$ (300,219,000)	$ 0
CARES Act
Unusual or Infrequent Item, or Both [Line Items]
Amount recorded to deferred payroll liability for unused PSP proceeds due to COVID-19	142,900,000		266,800,000
Special credits	142,900,000		266,800,000
CARES Act Employee Retention Credit
Unusual or Infrequent Item, or Both [Line Items]
Special credits	7,800,000		$ 35,800,000
COVID-19 Pandemic
Unusual or Infrequent Item, or Both [Line Items]
Severance costs and costs for voluntary separations	$ 2,400,000