Segment Information - Schedule of Segment Information by Regions (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Services revenue
Services revenue	$ 1,177.2	$ 1,086.9	$ 1,663.7
Cost of services (exclusive of depreciation and amortization)	997.4	1,056.5	1,435.6
General and administrative expenses
General and administrative expenses	88.2	85.4	109.0
Depreciation and amortization
Depreciation expense and amortization	25.1	29.3	29.4
Impairment of goodwill and intangible assets
Impairment of goodwill and intangible assets	0.0	135.3	0.0
Operating income (loss)
Total operating income (loss)	66.5	(219.6)	89.7
Lease Type Contracts
Services revenue
Services revenue	215.6	189.4	408.9
Cost of services (exclusive of depreciation and amortization)	170.6	195.0	366.9
Management Type Contracts
Services revenue
Services revenue	385.9	359.6	526.0
Cost of services (exclusive of depreciation and amortization)	247.5	226.5	339.9
Reimbursed Management Type Contract Revenue
Services revenue
Services revenue	575.7	537.9	728.8
Cost of services (exclusive of depreciation and amortization)	575.7	537.9	728.8
Lease Impairment
Services revenue
Cost of services (exclusive of depreciation and amortization)	3.6	97.1	0.0
Operating Segments | Commercial
Services revenue
Services revenue	439.0	398.9	651.2
Cost of services (exclusive of depreciation and amortization)	301.2	413.6	504.7
General and administrative expenses
General and administrative expenses	21.4	18.6	31.9
Depreciation and amortization
Depreciation expense and amortization	13.5	13.5	12.4
Operating income (loss)
Total operating income (loss)	102.9	(46.8)	102.2
Operating Segments | Commercial | Lease Type Contracts
Services revenue
Services revenue	206.5	180.8	378.2
Cost of services (exclusive of depreciation and amortization)	165.4	187.7	345.1
Operating Segments | Commercial | Management Type Contracts
Services revenue
Services revenue	232.5	218.1	273.0
Cost of services (exclusive of depreciation and amortization)	132.3	128.8	159.6
Operating Segments | Commercial | Lease Impairment
Services revenue
Cost of services (exclusive of depreciation and amortization)	3.5	97.1
Operating Segments | Aviation
Services revenue
Services revenue	162.5	150.1	283.7
Cost of services (exclusive of depreciation and amortization)	120.5	105.0	202.1
General and administrative expenses
General and administrative expenses	11.8	12.0	18.3
Depreciation and amortization
Depreciation expense and amortization	8.4	12.7	14.0
Impairment of goodwill and intangible assets
Impairment of goodwill and intangible assets		135.3
Operating income (loss)
Total operating income (loss)	21.8	(114.9)	49.3
Operating Segments | Aviation | Lease Type Contracts
Services revenue
Services revenue	9.1	8.6	30.7
Cost of services (exclusive of depreciation and amortization)	5.2	7.3	21.8
Operating Segments | Aviation | Management Type Contracts
Services revenue
Services revenue	153.4	141.5	253.0
Cost of services (exclusive of depreciation and amortization)	115.2	97.7	180.3
Operating Segments | Aviation | Lease Impairment
Services revenue
Cost of services (exclusive of depreciation and amortization)	0.1
Segment Reconciling Items
General and administrative expenses
General and administrative expenses	55.0	54.8	58.8
Depreciation and amortization
Depreciation expense and amortization	3.2	3.1	3.0
Operating income (loss)
Total operating income (loss)	$ (58.2)	$ (57.9)	$ (61.8)