Business Segments - Income Statement Items (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Revenue:
Revenue	$ 8,350.9	$ 4,482.7	$ 21,394.2	$ 15,656.2
Gross profit:
Gross profit	197.5	214.0	573.0	686.6
Income from operations:
Income from operations	41.7	38.8	110.2	121.5
Corporate overhead - unallocated
Income from operations:
Income from operations	(22.6)	(17.4)	(63.1)	(55.3)
Aviation segment
Revenue:
Revenue	3,579.7	1,596.2	8,480.5	6,381.0
Gross profit:
Gross profit	113.0	97.6	277.1	282.6
Aviation segment | Operating Segments
Income from operations:
Income from operations	57.0	29.2	114.0	67.3
Land segment
Revenue:
Revenue	2,670.4	1,645.2	7,315.8	4,948.8
Gross profit:
Gross profit	62.6	84.3	225.9	275.4
Land segment | Operating Segments
Income from operations:
Income from operations	3.7	18.8	44.5	54.1
Marine segment
Revenue:
Revenue	2,100.7	1,241.2	5,597.8	4,326.4
Gross profit:
Gross profit	21.9	32.0	70.0	128.6
Marine segment | Operating Segments
Income from operations:
Income from operations	$ 3.6	$ 8.2	$ 14.8	$ 55.4