Consolidated Statements of Stockholders' Deficit - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Earnings (Deficit)	Accumulated Other Comprehensive Income (Loss)
Balance at Sep. 30, 2016	$ (276,166)	$ 1,446		$ (177,561)	$ (100,051)
Balance (in shares) at Sep. 30, 2016		144,571
Increase (Decrease) in Stockholders' Equity
Net earnings	215,076			215,076
Other comprehensive income (loss), net of tax	18,215				18,215
Repurchases of common stock	(346,051)	$ (161)	$ (25,299)	(320,591)
Repurchases of common stock (in shares)		(16,072)
Share-based compensation	10,507	$ 1	10,506
Share-based compensation (in shares)		122
Stock issued for stock options	14,803	$ 10	14,793
Stock issued for stock options (in shares)		964
Balance at Sep. 30, 2017	(363,616)	$ 1,296		(283,076)	(81,836)
Balance (in shares) at Sep. 30, 2017		129,585
Increase (Decrease) in Stockholders' Equity
Net earnings	258,047			258,047
Other comprehensive income (loss), net of tax	(8,155)				(8,155)
Repurchases of common stock	(166,701)	$ (100)	(11,866)	(154,735)
Repurchases of common stock (in shares)		(9,987)
Share-based compensation	10,519	$ 2	10,517
Share-based compensation (in shares)		178
Stock issued for stock options	1,350	$ 1	1,349
Stock issued for stock options (in shares)		150
Balance at Sep. 30, 2018	$ (268,556)	$ 1,199		(179,764)	(89,991)
Balance (in shares) at Sep. 30, 2018	119,926	119,926
Increase (Decrease) in Stockholders' Equity
Net earnings	$ 271,623			271,623
Other comprehensive income (loss), net of tax	(27,296)				(27,296)
Repurchases of common stock	(47,434)	$ (36)	(11,336)	(36,062)
Repurchases of common stock (in shares)		(3,562)
Share-based compensation	9,180	$ 2	9,178
Share-based compensation (in shares)		209
Stock issued for stock options	2,160	$ 2	$ 2,158
Stock issued for stock options (in shares)		152
Balance at Sep. 30, 2019	$ (60,323)	$ 1,167		$ 55,797	$ (117,287)
Balance (in shares) at Sep. 30, 2019	116,725	116,725