Subsequent Events (Details) - Subsequent event	1 Months Ended
	Feb. 28, 2022 $ / shares	Jan. 31, 2022 GBP (£) $ / shares
Subsequent events
Common stock, dividends declared (in dollars per share) | $ / shares	$ 0.2465	$ 0.2465
Notes payable | 1.875% Notes due 2027
Subsequent events
Principal amount		$ 250,000,000
Stated interest rate (as a percent)		1.875%
Price of par value (as a percent)		99.487%
Effective yield (as a percent)		1.974%
Notes payable | 2.500% Notes due 2042
Subsequent events
Principal amount		$ 250,000,000
Stated interest rate (as a percent)		2.50%
Price of par value (as a percent)		98.445%
Effective yield (as a percent)		2.584%
Notes payable | January 2027 Notes And January 2042 Notes
Subsequent events
Effective yield (as a percent)		2.28%
Weighted average term (in years)		12 years 6 months