TREASURY STOCK (Details) $ / shares in Units, $ in Thousands			6 Months Ended		7 Months Ended	33 Months Ended
	Feb. 02, 2018 USD ($) shares	Feb. 01, 2018 USD ($) Dealer	Sep. 30, 2018 USD ($) shares	Sep. 30, 2017 USD ($) shares	Aug. 31, 2018 $ / shares shares	Mar. 31, 2018 USD ($) shares	Jan. 16, 2018 shares	Oct. 24, 2017 shares	May 19, 2015 shares
Equity, Class of Treasury Stock [Line Items]
Stock authorized to repurchase under stock repurchase program (in shares)							25,000,000
Shares repurchased during the period, value | $			$ 0	$ 200,000
Amount borrowed for repurchase | $		$ 300,000
Share repurchase program, May 2015
Equity, Class of Treasury Stock [Line Items]
Stock authorized to repurchase under stock repurchase program (in shares)									20,000,000
Shares repurchased during the period (in shares)	970,650			2,780,433		20,000,000
Shares repurchased during the period, value | $	$ 27,600			$ 100,000		$ 607,600
Stock remaining to be purchased (in shares)						0
Share repurchase program, October 2017
Equity, Class of Treasury Stock [Line Items]
Stock authorized to repurchase under stock repurchase program (in shares)								25,000,000
Shares repurchased during the period (in shares)	6,417,212
Shares repurchased during the period, value | $	$ 182,400
ASR Agreements
Equity, Class of Treasury Stock [Line Items]
Stock repurchase program, number of dealers | Dealer		2
Shares repurchased during the period (in shares)	7,387,862		3,679,947		11,067,809
Shares repurchased during the period, average cost per share | $ / shares					$ 27.11
Shares repurchased during the period, value | $	$ 150,000	$ 300,000	$ 96,800
Stock remaining to be purchased (in shares)			14,902,841
Number of shares acquired from each of dealers	3,693,931
Percentage of total number of shares expected to be repurchased	70.00%
Restricted stock units
Equity, Class of Treasury Stock [Line Items]
Shares paid for tax withholding			371,726
Cost related to tax withholding | $			$ 9,900