Special Credits - Narrative (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Unusual or Infrequent Item, or Both [Line Items]
Special credits	$ (151,911,000)	$ 0	$ (151,911,000)	$ 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	237,900,000		238,400,000
Payments of financing costs	500,000
Special credits	123,900,000		123,900,000
CARES Act Employee Retention Credit
Unusual or Infrequent Item, or Both [Line Items]
Special credits	$ 28,000,000.0		$ 28,000,000.0