Other Income, Net (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
AFUDC - Equity	$ 18.0	$ 20.9	$ 14.4
Earnings from equity method investments	158.1	175.8	127.6
Other income, net	133.2	79.5	102.2
Other income, net
Non-service components of net periodic benefit costs	72.2	41.2	36.2
AFUDC - Equity	18.0	20.9	14.4
Gains from investments held in rabbi trust	18.6	12.7	21.2
Earnings from equity method investments	19.9	2.4	3.5
Other, net	4.5	2.3	26.9
Other income, net	$ 133.2	$ 79.5	$ 102.2