Debt - Revolving Credit Facilities (Details)	Sep. 30, 2021 USD ($)
Line of Credit Facility [Line Items]
Total Commitments	$ 2,115,000,000
Total Outstanding	264,000,000
Total Available	1,827,000,000
Senior Secured Domestic Revolving Credit Facility
Line of Credit Facility [Line Items]
Total Commitments	1,850,000,000
Total Outstanding	174,000,000
Total Available	1,652,000,000
Standby letters of credit issued	24,000,000
Senior Secured International Revolving Credit Facility
Line of Credit Facility [Line Items]
Total Commitments	212,000,000
Total Outstanding	85,000,000
Total Available	127,000,000
Other International Facilities
Line of Credit Facility [Line Items]
Total Commitments	53,000,000
Total Outstanding	5,000,000
Total Available	$ 48,000,000