Business Segments, Geographic Information and Major Customers - Balance Sheet Items (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Accounts receivable, net:
Accounts receivable, net	$ 2,891.9	$ 2,739.6
Total assets:
Total assets	5,992.4	5,676.9
Corporate
Total assets:
Total assets	296.8	113.6
Aviation segment
Accounts receivable, net:
Accounts receivable, net	1,098.2	992.2
Allowance for bad debt	14.6	17.7
Aviation segment | Operating Segments
Total assets:
Total assets	2,416.5	2,261.0
Land segment
Accounts receivable, net:
Accounts receivable, net	863.2	846.1
Allowance for bad debt	2.8	2.7
Land segment | Operating Segments
Total assets:
Total assets	2,089.4	2,178.1
Marine segment
Accounts receivable, net:
Accounts receivable, net	930.5	901.2
Allowance for bad debt	18.0	19.0
Marine segment | Operating Segments
Total assets:
Total assets	$ 1,189.7	$ 1,124.2