Commitments and Contingencies (Labor Unions) (Details) - Workforce Subject to Collective Bargaining Arrangements [Member] - Labor Unions [Member]	3 Months Ended
Mar. 31, 2019
ABX [Member]
Concentration Risk [Line Items]
Percentage of the Company's Employees	6.30%
ATI [Member]
Concentration Risk [Line Items]
Percentage of the Company's Employees	6.60%
Omni Air International [Member]
Concentration Risk [Line Items]
Percentage of the Company's Employees	7.00%
Air Transport International, Flight Attendants [Member]
Concentration Risk [Line Items]
Percentage of the Company's Employees	1.00%
Omni Air International, Flight Attendants [Member] [Member]
Concentration Risk [Line Items]
Percentage of the Company's Employees	8.00%

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 18
-URI http://asc.fasb.org/extlink&oid=99393423&loc=d3e6351-108592

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=109250915&loc=d3e13531-108611

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 21
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109250915&loc=d3e13537-108611

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=99393423&loc=d3e6404-108592

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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration