Business Segments - Balance Sheet Items (Details) - USD ($) $ in Millions	Mar. 31, 2020	Jan. 01, 2020	Dec. 31, 2019
Accounts receivable, net:
Accounts receivable, net	$ 1,985.1		$ 2,891.9
Allowance for credit losses	56.1	$ 46.6	35.5
Total assets:
Total assets	5,498.9		5,992.4
Aviation segment
Accounts receivable, net:
Accounts receivable, net	606.5		1,098.2
Allowance for credit losses	22.2		14.6
Land segment
Accounts receivable, net:
Accounts receivable, net	728.1		863.2
Allowance for credit losses	8.3		2.8
Marine segment
Accounts receivable, net:
Accounts receivable, net	650.5		930.5
Allowance for credit losses	22.4		18.0
Operating Segments | Aviation segment
Total assets:
Total assets	2,215.2		2,416.5
Operating Segments | Land segment
Total assets:
Total assets	2,115.9		2,089.4
Operating Segments | Marine segment
Total assets:
Total assets	1,059.3		1,189.7
Corporate
Total assets:
Total assets	$ 108.5		$ 296.8