STOCKHOLDERS' EQUITY AND EQUITY COMPENSATION (Details)						3 Months Ended	12 Months Ended			48 Months Ended
	Apr. 16, 2018 USD ($) $ / shares	Mar. 07, 2018 USD ($) $ / shares	Jan. 17, 2017 USD ($) shares	Jul. 14, 2016 USD ($)	Jan. 29, 2016 shares	Sep. 30, 2017 $ / shares shares	Sep. 30, 2019 USD ($) senior_executive $ / shares shares	Sep. 30, 2018 USD ($) $ / shares shares	Sep. 30, 2017 USD ($) $ / shares shares	Jan. 29, 2020 shares	Nov. 13, 2019 $ / shares	Jun. 19, 2018 shares	Jan. 31, 2018 shares	Oct. 02, 2017	Aug. 31, 2016 USD ($)	May 18, 2016	Mar. 22, 2016 USD ($)	Jul. 31, 2015 USD ($)	Mar. 31, 2015 USD ($)	Jun. 18, 2014 USD ($)	Feb. 27, 2014	Aug. 31, 2011 USD ($)	Dec. 21, 2009 USD ($)	Dec. 31, 2008 shares
STOCKHOLDERS' EQUITY AND EQUITY COMPENSATION (Details) [Line Items]
Options Outstanding & Exercisable Shares (in Shares) | shares						350,000		350,000	350,000
Options Outstanding & Exercisable Weighted Average Exercise Price (in Dollars per Share) | $ / shares						$ 20.00		$ 20.00	$ 20.00
Common stock, dividends, per share, cash paid (in Dollars per share) | $ / shares							$ 0.29	$ 0.28	$ 0.24
Share-based payment award, description							Options granted under the Incentive Plan may be either “incentive stock options” or nonqualified stock options, generally expire ten years after the date of grant and are granted at an exercise price of not less than 100% of the fair market value at the date of grant.
Share-based payment award, expiration period					10 years
Maximum percentage of exercise price at grant date fair value					100.00%
Share-based payment award, number of shares authorized (in Shares) | shares							3,984,510
Share-based payment award, options, vested in period, fair value | $							$ 4,748,000	$ 11,216,000	$ 29,508,000
Employee service share-based compensation, nonvested awards, compensation not yet recognized, share-based awards other than options | $							$ 20,358,000
Employee service share-based compensation, nonvested awards, compensation cost not yet recognized, period for recognition							1 year 10 months 24 days
Stock repurchased during period, shares (in Shares) | shares							37,500
Stock repurchased during period, value | $							$ 372,000
Stock repurchased during period per share (in Dollars per share) | $ / shares							$ 9.92
Stock repurchase program, authorized amount | $															$ 50,000,000			$ 50,000,000	$ 50,000,000			$ 50,000,000
Stock repurchase program, remaining authorized repurchase amount | $							$ 57,955,000
Shares paid for tax withholding for share based compensation (in Shares) | shares							85,847
Shares paid for tax withholding for share based compensation, value | $							$ 1,059,000
Shares paid for tax withholding for share based compensation, value per share (in Dollars per share) | $ / shares							$ 12.34
Stock issued during period, shares, ESOP | shares								621,875
Common Stock, Number of Shares Held by Shareholder | shares												5,583,375
Debt instrument, face amount | $															$ 35,092,000
Issuance of treasury stock in settlement of convertible debt | $									$ 48,858,000
GS Direct [Member]
STOCKHOLDERS' EQUITY AND EQUITY COMPENSATION (Details) [Line Items]
Investment Owned, Balance, Shares | shares																								10,000,000
Incentive Plan [Member]
STOCKHOLDERS' EQUITY AND EQUITY COMPENSATION (Details) [Line Items]
Share-based payment award, number of shares authorized (in Shares) | shares					3,350,000
Incentive Stock Options [Member]
STOCKHOLDERS' EQUITY AND EQUITY COMPENSATION (Details) [Line Items]
Stock issued during period, shares, new issues (in Shares) | shares					600,000
Share-based payment award, number of shares available for grant (in Shares) | shares							270,937
2006 Equity Incentive Plan [Member]
STOCKHOLDERS' EQUITY AND EQUITY COMPENSATION (Details) [Line Items]
Share based payment award equity instruments other than options additional grants in future (in Shares) | shares							0
Restricted Stock [Member]
STOCKHOLDERS' EQUITY AND EQUITY COMPENSATION (Details) [Line Items]
Vested (in Dollars per share) | $ / shares							$ 13.15
Instruments grants in period (in shares) | shares							1,262,270
Weighted average grant date fair value (in Dollars per share) | $ / shares							$ 10.11
Shares paid for tax withholding for share based compensation (in Shares) | shares							3,861
Shares paid for tax withholding for share based compensation, value | $							$ 47,000
Shares paid for tax withholding for share based compensation, value per share (in Dollars per share) | $ / shares							$ 12.16
Instruments vested in period (in shares) | shares							361,152
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value | $ / shares							$ 12.96	$ 14.89
Restricted Stock [Member] | Minimum [Member]
STOCKHOLDERS' EQUITY AND EQUITY COMPENSATION (Details) [Line Items]
Share-based payment award, award vesting period							3 years
Restricted Stock [Member] | Maximum [Member]
STOCKHOLDERS' EQUITY AND EQUITY COMPENSATION (Details) [Line Items]
Share-based payment award, award vesting period							4 years
Performance Shares [Member]
STOCKHOLDERS' EQUITY AND EQUITY COMPENSATION (Details) [Line Items]
Share-based payment award, award vesting period							3 years
Instruments vested in period, fair value | $							$ 9,185,000
Instruments grants in period (in shares) | shares						0	1,262,270
Weighted average grant date fair value (in Dollars per share) | $ / shares							$ 12.51
Restricted Stock and Performance Shares [Member]
STOCKHOLDERS' EQUITY AND EQUITY COMPENSATION (Details) [Line Items]
Instruments grants in period (in shares) | shares							734,270
Executive Officer [Member] | Restricted Stock [Member]
STOCKHOLDERS' EQUITY AND EQUITY COMPENSATION (Details) [Line Items]
Share-based payment award, award vesting period							4 years
Post-vesting holding period							2 years
Instruments number of persons granted shares (in shares) | senior_executive							2
Executive Officer [Member] | Performance Shares [Member]
STOCKHOLDERS' EQUITY AND EQUITY COMPENSATION (Details) [Line Items]
Equity instruments other than options, granted in period, fair value | $							$ 3,576,000
Weighted average grant date fair value (in Dollars per share) | $ / shares							$ 6.77
Executive Officer [Member] | Restricted Stock and Performance Shares [Member]
STOCKHOLDERS' EQUITY AND EQUITY COMPENSATION (Details) [Line Items]
Instruments grants in period (in shares) | shares							528,000
Forecast [Member] | Executive Officer [Member] | Restricted Stock [Member] | Minimum [Member]
STOCKHOLDERS' EQUITY AND EQUITY COMPENSATION (Details) [Line Items]
Instruments vested in period (in shares) | shares										384,000
Forecast [Member] | Executive Officer [Member] | Restricted Stock [Member] | Maximum [Member]
STOCKHOLDERS' EQUITY AND EQUITY COMPENSATION (Details) [Line Items]
Instruments vested in period (in shares) | shares										528,000
Subsequent Event [Member]
STOCKHOLDERS' EQUITY AND EQUITY COMPENSATION (Details) [Line Items]
Dividends payable, amount per share (in Dollars per share) | $ / shares											$ 0.0750
Convert. debt due 2017 [Member]
STOCKHOLDERS' EQUITY AND EQUITY COMPENSATION (Details) [Line Items]
Debt instrument, face amount | $																							$ 100,000,000
Debt Instrument, Interest Rate, Stated Percentage																							4.00%
ESOP Loans [Member]
STOCKHOLDERS' EQUITY AND EQUITY COMPENSATION (Details) [Line Items]
Stock issued during period, value, ESOP | $								$ 10,908,000
ESOP, weighted average purchase price of shares purchased (in Dollars per share) | $ / shares								$ 17.54
Incentive Plan [Member]
STOCKHOLDERS' EQUITY AND EQUITY COMPENSATION (Details) [Line Items]
Share-based payment award, number of shares authorized (in Shares) | shares													1,000,000
Revolver Due 2020 [Member]
STOCKHOLDERS' EQUITY AND EQUITY COMPENSATION (Details) [Line Items]
Line of Credit Facility, Current Borrowing Capacity | $																	$ 350,000
Senior Notes Two Thousand Twenty Two [Member]
STOCKHOLDERS' EQUITY AND EQUITY COMPENSATION (Details) [Line Items]
Debt instrument, face amount | $																				$ 600,000,000
Debt Instrument, Interest Rate, Stated Percentage														5.25%		5.25%					5.25%
Original debt, amount | $				$ 125,000,000
Convertible Notes 2017 [Member]
STOCKHOLDERS' EQUITY AND EQUITY COMPENSATION (Details) [Line Items]
Debt Conversion, Converted Instrument, Amount | $			$ 173,855,000
Debt conversion, converted instrument, cash received | $			125,000,000
Issuance of treasury stock in settlement of convertible debt | $			$ 48,858,000
Converted instrument, shares issued | shares			1,954,993,000
Special Dividends [Member]
STOCKHOLDERS' EQUITY AND EQUITY COMPENSATION (Details) [Line Items]
Common stock, dividends, per share, cash paid (in Dollars per share) | $ / shares	$ 1.00
Common Stock, Dividends, Per Share, Declared | $ / shares		$ 1.00
Dividends, Common Stock, Cash | $		$ 38,073,000
Payments of Dividends | $	$ 38,073,000