Equity Incentive Plans - Option grant assumptions (Details) - Stock options	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Assumptions used to determine fair value of options granted
Weighted average expected term	5 years 10 months 24 days	7 years 6 months	6 years 1 month 6 days
Expected volatility, low end of the range (as a percent)	19.80%	16.50%	16.30%
Expected volatility, high end of the range (as a percent)	29.90%	28.80%	37.10%
Weighted average volatility (as a percent)	23.20%	23.00%	17.60%
Expected dividends, minimum range (as a percent)	2.50%	2.00%	1.60%
Expected dividends, maximum range (as a percent)	3.00%	3.00%	2.40%
Weighted average expected dividends (as a percent)	2.80%	3.10%	1.80%
Risk-free rate, low end of the range (as a percent)	0.00%	0.00%	0.10%
Risk-free rate, high end of the range (as a percent)	4.80%	1.70%	1.80%