Acquisitions (Details) $ in Millions	Oct. 18, 2017 facility	Sep. 19, 2017 USD ($) facility	Apr. 10, 2017 USD ($) aircraft	Dec. 04, 2015 USD ($)	May 31, 2018 USD ($)	May 31, 2017 USD ($)	May 31, 2016 USD ($)
Fair value of net assets acquired
Goodwill					$ 118.7	$ 105.6	$ 107.5
MRO facilities acquired in Canada owned by Premier Aviation
Acquisitions
Number of facilities acquired | facility	2	2
Total consideration		$ 24.8
Deferred consideration payable		1.9
Purchase price		22.9
Fair value of net assets acquired
Current assets		4.1
Property and equipment		13.1
Intangible assets, including goodwill		16.0
Accounts payable and accrued liabilities		(8.4)
Net assets acquired		$ 24.8
ACLAS
Acquisitions
Deferred consideration payable			$ 3.0
Number of aircrafts under multi-year component support and repair contract | aircraft			100
Deferred consideration payable period			3 years
Purchase price			$ 12.0
Fair value of net assets acquired
Inventory			5.0
Equipment on or available for long-term lease			6.2
Intangible assets			3.8
Assets acquired, net			$ 15.0
Vantem Modular LLC
Acquisitions
Purchase price				$ 4.8
Fair value of net assets acquired
Current assets				1.5
Equipment				0.5
Intangible assets				3.5
Contingent consideration				(2.0)
Assets acquired, net				3.5
Goodwill				1.3
Vantem Modular LLC | Maximum
Acquisitions
Future royalties				$ 5.0