Short-Term Borrowings and Long-Term Debt - Senior Notes (Details) - USD ($)				1 Months Ended
	May 13, 2021	Feb. 02, 2021	Jun. 05, 2020	Jan. 31, 2015	Jun. 30, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Long-term debt					$ 1,834,000,000	$ 844,000,000
Senior Notes | 3.125% Senior Notes
Debt Instrument [Line Items]
Debt issuance, principal value			$ 500,000,000		$ 500,000,000
Interest rate on senior notes			3.125%		3.125%
Net proceeds from debt			$ 495,000,000
Long-term debt					$ 495,000,000	$ 495,000,000
Debt issuance costs					4,000,000
Debt instrument, unamortized discount (less than excluding $2 million)					1,000,000
Senior Notes | 3.50% Senior Notes
Debt Instrument [Line Items]
Debt issuance, principal value				$ 350,000,000	$ 350,000,000
Interest rate on senior notes				3.50%	3.50%	3.50%
Net proceeds from debt				$ 346,000,000
Long-term debt					$ 349,000,000	$ 349,000,000
Debt issuance costs					1,000,000
Debt instrument, unamortized discount (less than excluding $2 million)					$ 1,000,000
Senior Notes | 1.800% Senior Notes
Debt Instrument [Line Items]
Debt issuance, principal value		$ 500,000,000
Interest rate on senior notes		1.80%			1.80%
Net proceeds from debt		$ 494,000,000
Long-term debt					$ 494,000,000	0
Debt issuance costs					4,000,000
Debt instrument, unamortized discount (less than excluding $2 million)					$ 2,000,000
Senior Notes | 2.100% Senior Notes
Debt Instrument [Line Items]
Debt issuance, principal value	$ 500,000,000	$ 500,000,000
Interest rate on senior notes	2.10%				2.10%
Net proceeds from debt	$ 496,000,000
Long-term debt					$ 496,000,000	$ 0
Debt issuance costs					4,000,000
Debt instrument, unamortized discount (less than excluding $2 million)					$ 1,000,000