Short-Term Borrowings and Long-Term Debt - Outstanding Short Term Borrowings and Long Term Debt (Details) - USD ($)	Dec. 31, 2021	Oct. 28, 2021	May 13, 2021	Feb. 02, 2021	Dec. 31, 2020	Jun. 05, 2020	Jan. 31, 2015
Debt Outstanding [Line Items]
Short-term borrowings	$ 121,000,000				$ 21,000,000
Total long-term debt	$ 2,570,000,000				844,000,000
Senior Notes | 3.50% Senior Notes
Debt Outstanding [Line Items]
Stated interest rate	3.50%						3.50%
Principal value	$ 350,000,000						$ 350,000,000
Total long-term debt	$ 349,000,000				349,000,000
Senior Notes | 3.125% Senior Notes
Debt Outstanding [Line Items]
Stated interest rate	3.125%					3.125%
Principal value	$ 500,000,000					$ 500,000,000
Total long-term debt	$ 496,000,000				495,000,000
Senior Notes | 1.800% Senior Notes
Debt Outstanding [Line Items]
Stated interest rate	1.80%			1.80%
Principal value	$ 500,000,000			$ 500,000,000
Total long-term debt	$ 494,000,000				0
Senior Notes | 2.100% Senior Notes
Debt Outstanding [Line Items]
Stated interest rate	2.10%		2.10%
Principal value	$ 500,000,000		$ 500,000,000
Total long-term debt	$ 496,000,000				0
Senior Notes | 1.800% Senior Notes
Debt Outstanding [Line Items]
Stated interest rate	1.80%	1.80%
Principal value	$ 650,000,000	$ 650,000,000
Total long-term debt	645,000,000				0
Junior subordinated debentures
Debt Outstanding [Line Items]
Principal value	100,000,000
Total long-term debt	90,000,000				0
Other short-term borrowings
Debt Outstanding [Line Items]
Principal value	60,000,000
Short-term borrowings	60,000,000				21,000,000
Securities sold under agreement to repurchase
Debt Outstanding [Line Items]
Principal value	61,000,000
Short-term borrowings	$ 61,000,000				$ 0