Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive (Loss) Income	Noncontrolling Interest
Beginning balance (shares) at Sep. 30, 2015		53,696
Beginning balance at Sep. 30, 2015	$ 656,031	$ 537	$ 310,038	$ 400,552	$ (55,096)	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock compensation	9,152		9,152
Release of restricted stock (shares)		403
Release of restricted stock	4	$ 4
Excess tax deficiency from stock compensation	(295)		(295)
Taxes paid related to net share settlement of equity awards	(172)		(172)
Amounts reclassified from accumulated other comprehensive loss	21				21
Foreign currency translation adjustment	(14,187)				(14,187)
Foreign currency translation reclassification upon disposition of Grupo Finmart	25,173				25,173
Acquisition of noncontrolling interest	246					246
Net income (loss)	(81,768)			(80,744)		(1,024)
Ending balance (shares) at Sep. 30, 2016		54,099
Ending balance at Sep. 30, 2016	594,205	$ 541	318,723	319,808	(44,089)	(778)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock compensation	5,831		5,831
Release of restricted stock (shares)		299
Release of restricted stock	3	$ 3
Taxes paid related to net share settlement of equity awards	(767)		(767)
Reclassification of 2019 Convertible Notes Warrants to liabilities	(523)		(523)
Foreign currency translation adjustment	5,701				5,722	(21)
Equity classified conversion feature of Convertible Notes, net of tax	25,268		25,268
Net income (loss)	30,208			31,858		(1,650)
Ending balance (shares) at Sep. 30, 2017		54,398
Ending balance at Sep. 30, 2017	659,926	$ 544	348,532	351,666	(38,367)	(2,449)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock compensation	10,711		10,711
Release of restricted stock (shares)		187
Release of restricted stock	2	$ 2
Taxes paid related to net share settlement of equity awards	(311)		(311)
Reclassification of stranded tax effects resulting from the Tax Cuts and Jobs Act	0			1,455	(1,455)
Foreign currency translation adjustment	(2,688)				(2,794)	106
Equity classified conversion feature of Convertible Notes, net of tax	38,995		38,995
Net income (loss)	38,071			39,059		(988)
Ending balance (shares) at Sep. 30, 2018		54,585
Ending balance at Sep. 30, 2018	$ 744,706	$ 546	$ 397,927	$ 392,180	$ (42,616)	$ (3,331)