SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2015
Inventory [Line Items]
Allowance for doubtful accounts	$ 1.2	$ 1.2	$ 3.8
Provision for doubtful accounts		5.6	3.7	$ 1.0
Inventory, net of reserves for excess and obsolete inventory	8.8	8.8	5.3
Inventory write down	3.9	3.9
Deferred fees	0.8	0.8	4.7
Deferred costs	0.5	$ 0.5	$ 3.1
Minimum [Member]
Inventory [Line Items]
Inventory reserves		3.00%
Maximum [Member]
Inventory [Line Items]
Inventory reserves		5.00%
Stock Options [Member]
Inventory [Line Items]
Outstanding stock options excluded in the calculation of earnings per share		2,471,230	866,000	0
Prepaid Expenses, Deferred Costs, and Other Current Assets [Member] | Accounting Standards Update 2015-03 [Member]
Inventory [Line Items]
Deferred finance costs, current					$ (1.7)
Deferred Credits and Other Assets [Member] | Accounting Standards Update 2015-03 [Member]
Inventory [Line Items]
Deferred finance costs, noncurrent					(6.0)
Long-term Debt [Member] | Accounting Standards Update 2015-03 [Member]
Inventory [Line Items]
Deferred finance costs, current					1.7
Deferred finance costs, noncurrent					$ 6.0
Deferred Costs [Member]
Inventory [Line Items]
Deferred drydocking	$ 1.8	$ 1.8	$ 1.3
Contract Drilling Costs [Member]
Inventory [Line Items]
Foreign exchange gain (loss)		$ (2.4)	$ (2.7)	$ (3.0)