Borrowings Under Credit Facilities and Commercial Paper Program - Narrative (Details)	1 Months Ended	12 Months Ended
	Jan. 31, 2019 USD ($)	Dec. 31, 2021 USD ($) bank	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Line of Credit Facility [Line Items]
Number of banks in consortium | bank		34
Borrowings outstanding		$ 324,935,000	$ 0
Total outstanding balance		13,910,273,000	2,378,073,000
Principal outstanding		325,000,000	$ 0	$ 1,588,600,000
Revolving Credit Facility
Line of Credit Facility [Line Items]
Unsecured line of credit arrangement		4,000,000,000
Borrowings outstanding		0
Available to borrow in alternate currencies (up to)		$ 1,000,000,000
Annual facility fee for each bank based on commitment amount		0.15%
Revolving Credit Facility | Credit Facility, Tranche Due 2023
Line of Credit Facility [Line Items]
Unsecured line of credit arrangement		$ 1,000,000,000
Borrowings outstanding		0
Revolving Credit Facility | Credit Facility, Tranche Due 2025
Line of Credit Facility [Line Items]
Unsecured line of credit arrangement		$ 3,000,000,000
Revolving Credit Facility | LIBOR
Line of Credit Facility [Line Items]
Applicable margin over index, based on certain debt ratings		0.775%
Revolving Credit Facility | Accordion Feature
Line of Credit Facility [Line Items]
Unsecured line of credit arrangement		$ 1,250,000,000
Term Credit Facility
Line of Credit Facility [Line Items]
Unsecured line of credit arrangement		500,000,000
Term Credit Facility, CAD Denominated
Line of Credit Facility [Line Items]
Unsecured line of credit arrangement		250,000,000
Term Credit Facility, CAD Denominated | Accordion Feature
Line of Credit Facility [Line Items]
Unsecured line of credit arrangement		250,000,000
Commercial Paper Note Program
Line of Credit Facility [Line Items]
Unsecured line of credit arrangement	$ 1,000,000,000
Commercial Paper Note Program | Maximum
Line of Credit Facility [Line Items]
Debt instrument, term	397 days
Commercial Paper Note Program | Line of Credit
Line of Credit Facility [Line Items]
Total outstanding balance		324,935,000
Principal outstanding		325,000,000
Unamortized discount		$ 65,000
Debt, Weighted Average Interest Rate		0.41%
Commercial Paper Note Program | Line of Credit | Weighted Average
Line of Credit Facility [Line Items]
Debt instrument, term		18 days