REVENUE RECOGNITION Remaining Performance Obligations (Details) $ in Thousands	3 Months Ended
	Jun. 30, 2019 USD ($)
Disaggregation of Revenue [Line Items]
Revenue, Remaining Performance Obligation, Remainder Fiscal Year	$ 340,408
Revenue, Remaining Performance Obligation, Rolling Year Two	229,327
Revenue, Remaining Performance Obligation, Rolling Year Three	192,800
Revenue, Remaining Performance Obligation, Rolling Year Four	186,633
Revenue, Remaining Performance Obligation, Rolling Year Five And Thereafter	285,269
Revenue, Remaining Performance Obligation, Amount	$ 1,234,437
Low
Disaggregation of Revenue [Line Items]
Revenue, Termination Period, Terms	30 days
High
Disaggregation of Revenue [Line Items]
Revenue, Termination Period, Terms	180 days
Helicopter Service Contracts [Member]
Disaggregation of Revenue [Line Items]
Revenue, Remaining Performance Obligation, Remainder Fiscal Year	$ 339,665
Revenue, Remaining Performance Obligation, Rolling Year Two	229,327
Revenue, Remaining Performance Obligation, Rolling Year Three	192,800
Revenue, Remaining Performance Obligation, Rolling Year Four	186,633
Revenue, Remaining Performance Obligation, Rolling Year Five And Thereafter	285,269
Revenue, Remaining Performance Obligation, Amount	1,233,694
Fixed Wing Service Contracts [Member]
Disaggregation of Revenue [Line Items]
Revenue, Remaining Performance Obligation, Remainder Fiscal Year	743
Revenue, Remaining Performance Obligation, Rolling Year Two	0
Revenue, Remaining Performance Obligation, Rolling Year Three	0
Revenue, Remaining Performance Obligation, Rolling Year Four	0
Revenue, Remaining Performance Obligation, Rolling Year Five And Thereafter	0
Revenue, Remaining Performance Obligation, Amount	$ 743