CONDENSED CONSOLIDATED STATEMENT OF SHAREHOLDERS' EQUITY - 6 months ended Mar. 31, 2017 - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	CAPITAL INEXCESS OFPAR VALUE [Member]	RETAINED EARNINGS [Member]	TREASURY SHARES [Member]	ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) [Member]	DEFERRED COMPENSATION [Member]
Balance at Sep. 30, 2016	$ 410,947	$ 19,992	$ 529,980	$ 475,760	$ (501,866)	$ (81,241)	$ (31,678)
Balance (in Shares) at Sep. 30, 2016		79,966			34,797
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	17,309			17,309
Dividend	(5,137)			(5,137)
Shares withheld on employee taxes on vested equity awards	(13,655)		(97)		$ 13,558
Shares withheld on employee taxes on vested equity awards					(582)
Amortization of deferred compensation	1,823						1,823
Common stock issued (shares)		3
Common stock issued	22	$ 0	22
Common stock acquired	(2,201)				$ (2,201)
Common stock acquired (in Shares)					129
Stock grants and equity awards, net (in Shares)		869
Equity awards granted, net	0	$ 217	(217)
Premium on settlement of convertible debt	73,855		(73,855)
Issuance of treasury stock in settlement of convertible debt	48,858		20,375		$ 28,483
Issuance of treasury stock in settlement of convertible debt (in shares)					(1,955)
ESOP purchase of common stock	9,213						9,213
ESOP allocation of common stock	1,611		1,611
Stock-based compensation	4,795		4,795
Other comprehensive income, net of tax	(3,379)					(3,379)
Balance at Mar. 31, 2017	$ 377,925	$ 20,209	$ 482,614	$ 487,932	$ (489,142)	$ (84,620)	$ (39,068)
Balance (in Shares) at Mar. 31, 2017		80,838			33,553