Acquisition of Business (Details) - USD ($) $ in Thousands	3 Months Ended								10 Months Ended	12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Nov. 09, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Business Acquisition [Line Items]
REVENUES	$ 403,351	$ 366,073	$ 334,576	$ 348,183	$ 280,779	$ 204,919	$ 203,607	$ 203,040		$ 1,452,183	$ 892,345	$ 1,068,200
Goodwill	395,974				390,745					395,974	390,745	37,279
Business Combination, Acquisition Related Costs										373	5,264	0
Long-term Debt	1,484,384				1,401,252					1,484,384	1,401,252
Business Combination, Separately Recognized Transactions, Additional Disclosures, Acquisition Cost Expensed									$ 5,300
Pro Forma [Member]
Business Acquisition [Line Items]
Depreciation									10,000			10,600
REVENUES											1,320,234	1,425,823
Business Acquisition, Pro Forma Income (Loss) from Continuing Operations, Net of Tax											88,454	$ 13,660
Omni Air [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents									4,693
Business Combination, Acquired Receivables, Estimated Uncollectible									63,041
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets									8,366
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Prepaid Expense and Other Assets									7,836
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill									140,000
Goodwill									353,466
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment									328,869
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities									(32,646)
Business Combination, Contingent Consideration, Liability									(5,950)
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net									867,675
Payments to Acquire Businesses, Gross									867,700
Revolving Credit Facility [Member]
Business Acquisition [Line Items]
Long-term Debt	$ 632,900				$ 475,000					$ 632,900	$ 475,000
Line of Credit Facility, Accordion Feature Amount									180,000
Senior Notes 2nd Term Loan [Member]
Business Acquisition [Line Items]
Long-term Debt									$ 675,000