Equity Incentive Plan - Valuation assumption (Details) - Performance units and shares [Member]	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (years)	2 years 10 months 24 days	2 years 10 months 24 days	2 years 10 months 24 days
Volatility	23.60%	33.50%	33.90%
Risk-free rate	4.40%	1.80%	0.20%