Employee Benefit Plans - Expected long-term return by asset category (Details)	12 Months Ended
	Dec. 31, 2021
Growth assets
Expected Long Term Return [Abstract]
Expected long-term return	7.00%
Asset allocation [Abstract]
Asset allocation	70.00%
Hedging assets
Expected Long Term Return [Abstract]
Expected long-term return	1.20%
Asset allocation [Abstract]
Asset allocation	28.00%
Cash
Expected Long Term Return [Abstract]
Expected long-term return	0.30%
Asset allocation [Abstract]
Asset allocation	2.00%