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Operating Income (Loss), After Interest Income (Expense)

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Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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This element represents acquisition-related costs incurred to effect a business combination which costs have been expensed during the period. Such costs include finder's fees; advisory, legal, accounting, valuation, and other professional or consulting fees; general administrative costs, including the costs of maintaining an internal acquisitions department; and may include costs of registering and issuing debt and equity securities.

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The current period expense charged against earnings on long-lived, physical assets not used in production, and which are not intended for resale, to allocate or recognize the cost of such assets over their useful lives; or to record the reduction in book value of an intangible asset over the benefit period of such asset; or to reflect consumption during the period of an asset that is not used in production.

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Aggregate net gain (loss) on all derivative instruments recognized in earnings during the period, before tax effects.

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Amount of income (loss) from continuing operations before deduction of income tax expense (benefit) and income (loss) attributable to noncontrolling interest, and addition of income (loss) from equity method investments.

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Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Amount of the cost of borrowed funds accounted for as interest expense.

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Amount of expense (reversal of expense) for net periodic benefit cost components, excluding service cost component, of defined benefit plan. Amount includes, but is not limited to, interest cost, expected (return) loss on plan asset, amortization of prior service cost (credit), amortization of (gain) loss, amortization of transition (asset) obligation, settlement (gain) loss, curtailment (gain) loss and certain termination benefits.

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Generally recurring costs associated with normal operations except for the portion of these expenses which can be clearly related to production and included in cost of sales or services. Includes selling, general and administrative expense.

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Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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No definition available.

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Segment Information (Segment Reconciliation) (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2017	Dec. 31, 2018
Segment Reporting Information [Line Items]
Operating Expenses	$ 301,655	$ 175,397
REVENUES	348,183	203,040
Customer revenues	348,183	203,040
Depreciation and amortization expense	62,637	40,004
Net unallocated interest expense	(17,390)	(5,362)
Net gain (loss) on financial instruments	4,500	(885)
Pre-tax earnings from continuing operations	27,567	20,928
Assets	2,631,962			$ 2,470,585
Income Tax Expense (Benefit)		5,246
Business Combination, Acquisition Related Costs	(373)	0
Net Periodic Defined Benefits Expense (Reversal of Expense), Excluding Service Cost Component	(2,351)	2,045
Customer Revenues [Member]
Segment Reporting Information [Line Items]
REVENUES	348,183	203,040
Customer revenues	348,183	203,040
Ground Services [Member] \| Customer Revenues [Member]
Segment Reporting Information [Line Items]
REVENUES	13,938		$ 16,154
Customer revenues	13,938		$ 16,154
All Other non MRO or Ground Services [Member] \| Customer Revenues [Member]
Segment Reporting Information [Line Items]
REVENUES	702	686
Customer revenues	702	686
CAM [Member]
Segment Reporting Information [Line Items]
REVENUES	70,350	52,376
Customer revenues	70,350	52,376
Depreciation and amortization expense	38,795	28,925
Segment earnings (loss)	16,174	15,464
Net unallocated interest expense	(10,000)	(4,500)
Assets	1,709,864			1,577,182
CAM [Member] \| Customer Revenues [Member]
Segment Reporting Information [Line Items]
REVENUES		35,887
Customer revenues		35,887
ACMI Services [Member]
Segment Reporting Information [Line Items]
REVENUES	257,956	119,374
Customer revenues	257,956	119,374
Depreciation and amortization expense	23,095	10,225
Segment earnings (loss)	12,310	3,415
Net unallocated interest expense	(6,500)	(500)
Assets	741,496			759,131
ACMI Services [Member] \| Customer Revenues [Member]
Segment Reporting Information [Line Items]
REVENUES		119,374
Customer revenues		119,374
Ground Services [Member] \| Customer Revenues [Member]
Segment Reporting Information [Line Items]
REVENUES	33,981	30,939
Customer revenues	33,981	30,939
All other [Member]
Segment Reporting Information [Line Items]
REVENUES	67,362	71,898
Customer revenues	67,362	71,898
Depreciation and amortization expense	747	854
Segment earnings (loss)	1,903	3,718
Assets	180,602			$ 134,272
All other [Member] \| Customer Revenues [Member]
Segment Reporting Information [Line Items]
REVENUES	48,621	47,779
Customer revenues	48,621	47,779
Significant Reconciling Items [Member]
Segment Reporting Information [Line Items]
Net unallocated interest expense	(780)	(293)
Non-operating charges from a non-consolidating affiliate	(3,816)	(2,536)
Eliminate inter-segment revenues [Member]
Segment Reporting Information [Line Items]
REVENUES	(47,485)	(40,608)
Customer revenues	(47,485)	$ (40,608)
Accounting Standards Update 2014-09 [Member]
Segment Reporting Information [Line Items]
Income Tax Expense (Benefit)	(4,933)
Accounting Standards Update 2014-09 [Member] \| CAM [Member] \| Customer Revenues [Member]
Segment Reporting Information [Line Items]
REVENUES	41,609
Customer revenues	41,609
Accounting Standards Update 2014-09 [Member] \| ACMI Services [Member] \| Customer Revenues [Member]
Segment Reporting Information [Line Items]
REVENUES	257,953
Customer revenues	257,953
Accounting Standards Update 2014-09 [Member] \| All other [Member] \| Customer Revenues [Member]
Segment Reporting Information [Line Items]
REVENUES	48,621
Customer revenues	$ 48,621