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SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - SALES TAX ACCOUNTING (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Jan. 01, 2018	Jan. 01, 2017
Principal Transaction Revenue [Line Items]
Sales tax	$ 13.3	$ 11.2
NEW JERSEY
Principal Transaction Revenue [Line Items]
State sales tax, percent		7.00%		6.875%
Subsequent Event | NEW JERSEY
Principal Transaction Revenue [Line Items]
State sales tax, percent			6.625%

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- Definition

Sales Tax

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- Definition

State Sales Tax, Percent

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