SHAREHOLDERS' EQUITY (Details)						3 Months Ended			6 Months Ended			12 Months Ended	68 Months Ended
	Mar. 31, 2017 USD ($) shares	Jan. 30, 2017 shares	Jan. 17, 2017 USD ($) shares	Jul. 14, 2016 USD ($)	May 04, 2016 $ / shares	Mar. 31, 2017 USD ($) senior_executive $ / shares shares	Dec. 31, 2016 USD ($) $ / shares shares	Mar. 31, 2016 USD ($) $ / shares	Mar. 31, 2017 USD ($) $ / shares shares	Mar. 31, 2016 USD ($) $ / shares	Mar. 31, 2015 shares	Sep. 30, 2016 USD ($) $ / shares	Mar. 31, 2017 USD ($) $ / shares shares	May 31, 2014 USD ($)	Feb. 27, 2014 USD ($)	Dec. 10, 2013 USD ($) shares	Oct. 21, 2013 USD ($)	Dec. 21, 2009 USD ($)
SHAREHOLDERS' EQUITY (Details) [Line Items]
Common stock, dividends, per share, cash paid (in Dollars per share) | $ / shares						$ 0.06		$ 0.05	$ 0.12	$ 0.10		$ 0.20
Dividends declared, amount per share (in Dollars per share) | $ / shares					$ 0.06
Share-based compensation arrangement by 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 compensation arrangement by share-based payment award, expiration period									10 years
Maximum percentage of exercise price at grand date fair value									100.00%
Stock-based compensation						$ 2,343,000		$ 2,489,000	$ 4,795,000	$ 5,555,000
Stock repurchase program, authorized amount														$ 50,000,000		$ 50,000,000
Stock Repurchased During Period, Shares | shares						129,000					4,444,444		15,984,854
Stock repurchased during period, value						$ 2,201,000							$ 211,621,000
Stock repurchased during period per share (in Dollars per share) | $ / shares						$ 17.06							$ 13.24
Stock repurchase program, remaining authorized repurchase amount	$ 49,437,000					$ 49,437,000			$ 49,437,000				$ 49,437,000
Shares paid for tax withholding for share based compensation (in Shares) | shares						27,431			582,478
Shares paid for tax withholding for share based compensation, value						$ 685,000			$ 13,558,000
Shares paid for tax withholding for share based compensation, value per share (in Dollars per share) | $ / shares						$ 24.97			$ 23.28
Face amount	$ 8,000,000					$ 8,000,000		$ 35,092,000	$ 8,000,000	$ 35,092,000		$ 32,280,000	$ 8,000,000				$ 36,012,000
Issuance of treasury stock in settlement of convertible debt									$ 48,858,000
Stock Repurchase Program, Remaining Number of Shares Authorized to be Repurchased | shares																5,555,556,000
Incentive Plan [Member]
SHAREHOLDERS' EQUITY (Details) [Line Items]
Number of shares authorized for award (in Shares) | shares	2,350,000					2,350,000			2,350,000				2,350,000
New shares issued (in Shares) | shares						600,000
Incentive Stock Options [Member]
SHAREHOLDERS' EQUITY (Details) [Line Items]
Number of shares available for grant (in Shares) | shares	1,068,362					1,068,362			1,068,362				1,068,362
2006 Equity Incentive Plan [Member]
SHAREHOLDERS' EQUITY (Details) [Line Items]
Share based compensation arrangement by share based payment award equity instruments other than options additional grants in future (in Shares) | shares	0					0			0				0
Performance Shares [Member]
SHAREHOLDERS' EQUITY (Details) [Line Items]
Equity instruments other than options, grants in period (in Shares) | shares							300,494
Award vesting period							3 years
Equity instruments other than options, vested in period, fair value							$ 6,055,000
Equity instruments other than options, grants in period, weighted average grant date fair value (in Dollars per share) | $ / shares							$ 20.15
Restricted Stock and Performance Shares [Member]
SHAREHOLDERS' EQUITY (Details) [Line Items]
Equity instruments other than options, grants in period (in Shares) | shares						528,000
Minimum [Member] | Restricted Stock [Member]
SHAREHOLDERS' EQUITY (Details) [Line Items]
Award vesting period									3 years
Maximum [Member] | Restricted Stock [Member]
SHAREHOLDERS' EQUITY (Details) [Line Items]
Award vesting period									4 years
Executive Officer [Member] | Restricted Stock [Member]
SHAREHOLDERS' EQUITY (Details) [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Number of Persons Granted Shares | senior_executive						2
Award vesting period						4 years
Share-based Compensation Arrangement by Share-based Payment Award, Award Post-Vesting Holding Period						2 years
Equity instruments other than options, vested in period, fair value	$ 8,500,000
Equity instruments other than options, grants in period, weighted average grant date fair value (in Dollars per share) | $ / shares							$ 16.10
Executive Officer [Member] | Minimum [Member] | Restricted Stock [Member]
SHAREHOLDERS' EQUITY (Details) [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period | shares		384,000
Executive Officer [Member] | Maximum [Member] | Restricted Stock [Member]
SHAREHOLDERS' EQUITY (Details) [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period | shares		528,000
Convert. debt due 2017 [Member]
SHAREHOLDERS' EQUITY (Details) [Line Items]
Face amount																		$ 100,000,000
Debt instrument, interest rate, stated percentage																		4.00%
Senior Notes 2022 [Member]
SHAREHOLDERS' EQUITY (Details) [Line Items]
Face amount															$ 600,000,000
Debt instrument, interest rate, stated percentage															5.25%
Debt conversion, original debt, amount				$ 125,000,000
Convertible Notes 2017 [Member]
SHAREHOLDERS' EQUITY (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
Debt conversion, converted instrument, shares issued | shares			1,954,993
Second Quarter [Member] | Executive Officer [Member] | Restricted Stock [Member]
SHAREHOLDERS' EQUITY (Details) [Line Items]
Equity instruments other than options, grants in period (in Shares) | shares						40,700
Share-based Compensation Arrangement by Share-based Payment Award, Award Post-Vesting Holding Period						3 years
Equity instruments other than options, vested in period, fair value							$ 1,036,000
Equity instruments other than options, grants in period, weighted average grant date fair value (in Dollars per share) | $ / shares						$ 25.45